Java Programs

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Program 1 - Write a program to print Hello World!.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    System.out.print("Hello,world!");
  }
}
Program 2 - Write a program to print Hello World!.
Solution: 
public class MyClass {
public static void main(String[] args) {
System.out.print("Hello,world!");
}
}
Program 3 - Write a program to compute the perimeter and area of a rectangle.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    int height = 8;
    int width = 5;
    int perimeter = 2 * (height + width);
    System.out.println("Perimeter of the rectangle is: " + perimeter + " cm");
    int area = height * width;
    System.out.println("Area of the rectangle is: " + area + " square cm");
  }
}
Program 4 - Write a program to compute the perimeter and area of a circle.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    int radius = 4;
    float perimeter = (float)(2 * 3.14 * radius);
    System.out.printf("Perimeter of the circle is: %f cm\n", perimeter);
    float area = (float)(3.14 * radius * radius);
    System.out.printf("Area of the circle is: %f square cm\n", area);
  }
}
Program 5 - Write a program that accepts two numbers from the user and calculate the sum of the two numbers.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int a, b, sum;
    System.out.print("\nEnter the first number: ");
    a = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the second number: ");
    b = STDIN_SCANNER.nextInt();
    sum = a + b;
    System.out.print("\nSum of the above two numbers is: " + sum);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 6 - Write a program that accepts two numbers from the user and calculate the product of the two numbers.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int a, b, mult;
    System.out.print("\nEnter the first number: ");
    a = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the second number: ");
    b = STDIN_SCANNER.nextInt();
    mult = a * b;
    System.out.print("\nProduct of the above two numbers is: " + mult);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 7 - Write a program that accepts three numbers and find the largest of three.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x, y, z;
    System.out.print("\nEnter the first number: ");
    x = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the second number: ");
    y = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the third number: ");
    z = STDIN_SCANNER.nextInt();

    // if x is greater than both y and z, x is the largest
    if(x >= y && x >= z) {
      System.out.print("\n" + x + " is the largest number.");
    }

    // if y is greater than both x and z, y is the largest
    if(y >= x && y >= z) {
      System.out.print("\n" + y + " is the largest number.");
    }

    // if z is greater than both x and y, z is the largest
    if(z >= x && z >= y) {
      System.out.print("\n" + z + " is the largest number.");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 8 - Write a program that reads three floating values and check if it is possible to make a triangle with them. Also calculate the perimeter of the triangle if the entered values are valid.
Solution: 

import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    float x, y, z;
    System.out.print("\nEnter the first number: ");
    x = STDIN_SCANNER.nextFloat();
    System.out.print("\nEnter the second number: ");
    y = STDIN_SCANNER.nextFloat();
    System.out.print("\nEnter the third number: ");
    z = STDIN_SCANNER.nextFloat();

    if(x < y + z && y < x + z && z < y + x) {
      System.out.printf("\nPerimeter of the triangle is: %f\n", x + y + z);
    } else {
      System.out.print("\nIt is impossible to form a triangle.");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 9 - Write a program that reads an integer between 1 and 7 and print the day of the week in English.
Solution: 

import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int day;
    System.out.print("\nEnter a number between 1 to 7 to get the day name: ");
    day = STDIN_SCANNER.nextInt();
    switch(day) {
      case 1:
        System.out.println("Monday");
        break;
      case 2:
        System.out.println("Tuesday");
        break;
      case 3:
        System.out.println("Wednesday");
        break;
      case 4:
        System.out.println("Thursday");
        break;
      case 5:
        System.out.println("Friday");
        break;
      case 6:
        System.out.println("Saturday");
        break;
      case 7:
        System.out.println("Sunday");
        break;
      default:
        System.out.print("Enter a number between 1 to 7.");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 10 - Write a program to find the sum of two numbers.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    int a, b, sum;
    a = 1;
    b = 2;
    sum = a + b;
    System.out.print("The sum of a and b = " + sum);
  }
}
Program 11 - Write a program to find the square of a number.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    int a, b;
    a = 2;
    b = (int)Math.pow(a, 2);
    System.out.print("The square of a = " + b);
  }
}
Program 12 - Write a program to find the greatest of two numbers.
Solution: 
public class MyClass {
  public static void main(String[] args) {
      int a, b;
      a = 2;
      b = 3;
      if(a > b) {
      System.out.print("a is greater than b");
    } else {
      System.out.print("b is greater than a");
    }
  }
}
Program 13 - Write a program to print the average of the elements in the array.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    int avg = 0, sum = 0;
    int[] num = {16, 18, 20, 25, 36};
    for(int i = 0; i < 5; i++) {
    sum = sum + num[i];
    avg = sum / 5;
    }
    System.out.println("Sum of the Elements in the array is: " + sum);
    System.out.println("Average of the elements in the array is: " + avg);
  }
}
Program 14 - Write a program that prints all even numbers between 1 and 25.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    System.out.println("Even numbers between 1 to 25:");
    for(int i = 1; i <= 25; i++) {
      if(i % 2 == 0) {
        System.out.print(i + " ");
      }
    }
  }
}
Program 15 - Write a program that prints all odd numbers between 1 and 50.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    System.out.println("Odd numbers between 1 to 50:");
    for(int i = 1; i <= 50; i++) {
      if(i % 2 != 0) {
        System.out.print(i + " ");
      }
    }
  }
}
Program 16 - Write a program to print the first 10 numbers starting from one together with their squares and cubes.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    for(int i = 1; i <= 10; i++) {
      System.out.println("Number = " + i + " its square = " + (i * i) + " its cube = " + (i * i * i));
    }
  }
}
Program 17 - Write a program: If you enter a character M, Output must be: ch = M.
Solution: 
public class MyClass {
  public static void main(String[] args) throws Exception {
    char c;
    System.out.print("Enter a character: ");
    c = (char)System.in.read();
    System.out.println("ch = " + c);
  }
}
Program 18 - Write a program to print the multiplication table of a number entered by the user.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int n;
    System.out.print("Enter any number: ");
    n = STDIN_SCANNER.nextInt();
    for(int i = 1; i <= 5; i++) {
      System.out.println(n + " * " + i + " = " + (n * i));
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 19 - Write a program to print the product of the first 10 digits.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    int product = 1;
    for(int i = 1; i <= 10; i++) {
      product = product * i;
    }
    System.out.print("The product of the first 10 digits is: " + product);
  }
}
Program 20 - Write a program to print whether the given number is positive or negative.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    int a;
    a = -35;
    if(a > 0) {
      System.out.print("Number is positive");
    } else {
      System.out.print("Number is negative");
    }
  }
}
Program 21 - Write a program to check the equivalence of two numbers entered by the user.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x, y;
    System.out.print("\nEnter the first number: ");
    x = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the second number: ");
    y = STDIN_SCANNER.nextInt();
    if(x - y == 0) {
      System.out.print("\nThe two numbers are equivalent");
    } else {
      System.out.print("\nThe two numbers are not equivalent");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 22 - Write a program to print the remainder of two numbers entered by the user.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int a, b, c;
    System.out.print("\nEnter the first number: ");
    a = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the second number: ");
    b = STDIN_SCANNER.nextInt();
    c = a % b;
    System.out.print("\n The remainder of " + a + " and " + b + " is: " + c);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 23 - Write a program to print the characters from A to Z.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    for(byte i = 'A'; i <= 'Z'; i++) {
      System.out.println((char)Byte.toUnsignedInt(i));
    }
  }
}
Program 24 - Write a program to print the length of the entered string.
Solution: 
import java.util.Scanner;
public class MyClass {
  public static void main(String[] args) {
    String a;
    Scanner scan = new Scanner(System.in);
    System.out.print("Enter Your Name : ");
    a = scan.nextLine();
    System.out.println("The length of the String is: " + a.length());
  }
}
Program 25 - Write a program to check whether the given character is a lower case letter or not.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    char ch = 'a';
    if(Character.isLowerCase(ch)) {
      System.out.println("The given character is a lower case letter");
    }
    else {
      System.out.println("The given character is a upper case letter");
    }
  }
}
Program 26 - Write a program to check whether the given character is a upper case letter or not.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    char ch = 'A';
    if(Character.isUpperCase(ch)) {
      System.out.println("The given character is a upper case letter");
    }
    else {
      System.out.println("The given character is a lower case letter");
    }
  }
}
Program 27 - Write a program to convert the lower case string to upper case string.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    String a = "albert einstein";
    System.out.println(a.toUpperCase());
  }
}
Program 28 - Write a program that takes a distance in centimeters and outputs the corresponding value in inches.
Solution: 
import java.util.Scanner;

public class MyClass {
  public final static double X = 2.54;
  public static void main(String[] args) {
    double inch, cm;
    System.out.print("Enter the distance in cm: ");
    cm = STDIN_SCANNER.nextDouble();
    inch = cm / X;
    System.out.printf("\nDistance of %.2f cms is equal to %.2f inches", cm, inch);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 29 - Write a program to print the output:
 Einstein [0] = E
Einstein [1] = I
Einstein [2] = N
Einstein [3] = S
Einstein [4] = T
Einstein [5] = E
Einstein [6] = I
Einstein [7] = N
Solution: 
public class MyClass {
  public static void main(String[] args) throws Exception{
    int i;
    char [] num = {'E' , 'I', 'N', 'S', 'T', 'E', 'I', 'N'};
    for(i=0; i<8; i++)
    System.out.println("Einstein [" + i + " ] = " + num[i]);
  }
}
Program 30 - Write a program to print "Hello World" 10 times.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    for(int i = 1; i <= 10; i++) {
      System.out.println("Hello World ");
    }
  }
}
Program 31 - Write a program to print first 5 numbers using do while loop statement.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    int i = 1;
    do {
      System.out.println(i++);
    } while(i <= 5);
  }
}
Program 32 - Write a program to check whether a character is an alphabet or not.
Solution: 
import java.util.Scanner;
public class Main {
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    System.out.println("Enter any caracter: ");
    char c = scanner.next().charAt(0);
    if((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) {
      System.out.println(c + " is a Alphabet.");
    } else {
      System.out.println(c + " is not a Alphabet.");
    }
  }
}
Program 33 - Write a program to check whether a entered number is even or odd.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int a;
    System.out.print("Enter any number: ");
    a = STDIN_SCANNER.nextInt();
    if(a % 2 == 0) {
      System.out.print("The entered number is even");
    } else {
      System.out.print("The entered number is odd");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 34 - Write a program to print the ASCII value of the given character.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    byte ch = 'A';
    System.out.print("The ASCII value of " + ((char)Byte.toUnsignedInt(ch)) + " is: " + ch);
  }
}
Program 35 - Write a program that will print all numbers between 1 to 50 which divided by a specified number and the remainder will be 2.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x;
    System.out.print("Enter a number: ");
    x = STDIN_SCANNER.nextInt();
    for(int i = 1; i <= 50; i++) {
      if(i % x == 2) {
        System.out.println(i);
      }
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 36 - Write a program to determine whether two numbers in a pair are in ascending or descending order.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int a, b;
    System.out.print("\nEnter a pair of numbers (for example 22,12 | 12,22): ");
    System.out.print("\nEnter the first number: ");
    a = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the second number: ");
    b = STDIN_SCANNER.nextInt();
    if(a > b) {
      System.out.print("\nThe two numbers in a pair are in descending order.");
    } else {
      System.out.print("\nThe two numbers in a pair are in ascending order.");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 37 - Write a program that reads two numbers and divides one by the other. Specify "Division not possible" if that is not possible.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int a, b;
    float c;
    System.out.print("\nEnter the first number: ");
    a = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the second number: ");
    b = STDIN_SCANNER.nextInt();
    if(b != 0) {
      c = (float)a / (float)b;
      System.out.printf("\n%d/%d = %.1f", a, b, c);
    } else {
      System.out.println("\nDivision not possible.");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 38 - Write a program that will print all numbers between 1 to 50 which divided by a specified number and the remainder is equal to 2 or 3.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x;
    System.out.print("Enter a number: ");
    x = STDIN_SCANNER.nextInt();
    for(int i = 1; i <= 50; i++) {
      if(i % x == 2 || i % x == 3) {
        System.out.println(i);
      }
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 39 - Write a program that adds up all numbers between 1 and 100 that are not divisible by 12.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    int x = 12, sum = 0;
    for(int i = 1; i <= 100; i++) {
      if(i % x != 0) {
        sum += i;
      }
    }
    System.out.println("\nSum: " + sum);
  }
}
Program 40 - Write a program to calculate the value of x where x = 1 + 1/2 + 1/3 + … + 1/50.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    float x = 0;
    for(int i = 1; i <= 50; i++) {
      x += (float)1 / i;
    }
    System.out.printf("Value of x: %.2f\n", x);
  }
}
Program 41 - Write a program that reads a number and find all its divisor.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x;
    System.out.print("\nEnter a number: ");
    x = STDIN_SCANNER.nextInt();
    System.out.print("All the divisor of " + x + " are: ");
    for(int i = 1; i <= x; i++) {
      if(x % i == 0) {
        System.out.print("\n" + i);
      }
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 42 - Write a program to find the incremented and decremented values of two numbers.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    int a, b, c, d, e, f;
    a = 10;
    b = 12;
    c = a + 1;
    d = b + 1;
    e = a - 1;
    f = b - 1;
    System.out.print("\nThe incremented value of a =" + c);
    System.out.print("\nThe incremented value of b =" + d);
    System.out.print("\nThe decremented value of a =" + e);
    System.out.print("\nThe decremented value of b =" + f);
  }
}
Program 43 - Write a program to find square of a entered number using functions.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int answer;
    answer = square();
    System.out.print("The square of the entered number is: " + answer);
  }

  public static int square() {
    int x;
    System.out.print("Enter any number: ");
    x = STDIN_SCANNER.nextInt();
    return x * x;
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 44 - Write a program that accepts principal amount, rate of interest, time and compute the simple interest.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int p, r, t, SI;
    System.out.print("\nEnter the principal amount: ");
    p = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the rate of interest: ");
    r = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the time: ");
    t = STDIN_SCANNER.nextInt();
    SI = (p * r * t) / 100;
    System.out.print("\nSimple interest is: " + SI);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 45 - Write a program that swaps two numbers without using third variable.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int a, b;
    System.out.print("\nEnter the value for a: ");
    a = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the value for b: ");
    b = STDIN_SCANNER.nextInt();
    System.out.print("\nBefore swapping: " + a + " " + b);
    a = a + b;
    b = a - b;
    a = a - b;
    System.out.print("\nAfter swapping: " + a + " " + b);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 46 - Write a program to compute the area of a hexagon.
Solution: 
import java.util.Scanner;
public class MyClass {
  public static void main(String[] args) {
    Scanner input = new Scanner(System.in);
    System.out.print("Enter the length of a side of the hexagon: ");
    double s = input.nextDouble();
    double area = (6*(s*s))/(4*Math.tan(Math.PI/6));
    System.out.print("The area of the hexagon is: " + area);
  }
}
Program 47 - Write a program to print the output:
 body [b] = b
body [o] = o
body [d] = d
body [y] = y
Solution: 
public class MyClass {
  public static void main(String[] args) throws Exception{
    int i;
    char [] body = {'b', 'o', 'd', 'y'};
    for(i=0; i<4; i++) {
      System.out.println("body [" + body [i] + " ] = " + body [i]);
    }
  }
}
Program 48 - Write a program to calculate the discounted price and the total price after discount
 Given:
If purchase value is greater than 1000, 10% discount
If purchase value is greater than 5000, 20% discount
If purchase value is greater than 10000, 30% discount.
Solution: 
import java.util.Scanner;
public class MyClass {
  public static void main(String[] args) {
    double pv;
    System.out.print("Enter purchased value: ");
    pv = STDIN_SCANNER.nextDouble();
    if(pv > 1000) {
      System.out.printf("\n Discount = %f", pv * 0.1);
      System.out.printf("\n Total = %f", pv - pv * 0.1);
    } else if(pv > 5000) {
      System.out.printf("\n Discount = %f", pv * 0.2);
      System.out.printf("\n Total = %f", pv - pv * 0.2);
    } else {
      System.out.printf("\n Discount = %f", pv * 0.3);
      System.out.printf("\n Total = %f", pv - pv * 0.3);
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 49 - Write a program to print the first ten natural numbers using while loop statement.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    int i = 1;
    while(i <= 10) {
      System.out.println(i++);
    }
  }
}
Program 50 - Write a program to shift inputted data by two bits to the left.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x;
    System.out.print("Enter the integer from keyboard: ");
    x = STDIN_SCANNER.nextInt();
    System.out.print("\nEntered value: " + x + " ");
    System.out.print("\nThe left shifted data is: " + (x <<= 2) + " ");
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 51 - Write a program to shift inputted data by two bits to the Right.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x;
    System.out.print("Enter the integer from keyboard: ");
    x = STDIN_SCANNER.nextInt();
    System.out.print("\nEntered value: " + x + " ");
    System.out.print("\nThe right shifted data is: " + (x >>= 2) + " ");
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 52 - Write a program to calculate the exact difference between x and 21. Return three times the absolute difference if x is greater than 21.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x;
    System.out.print("Enter the value for x: ");
    x = STDIN_SCANNER.nextInt();
    if(x <= 21) {
      System.out.print(Math.abs(x - 21));
    } else if(x >= 21) {
      System.out.print(Math.abs(x - 21) * 3);
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 53 - Write a program that reads in two numbers and determine whether the first number is a multiple of the second number.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x, y;
    System.out.print("\nEnter the first number: ");
    x = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the second number: ");
    y = STDIN_SCANNER.nextInt();
    if(x % y == 0) {
      System.out.println("\n" + x + " is a multiple of " + y + ".");
    } else {
      System.out.println("\n" + x + " is not a multiple of " + y + ".");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 54 - Write a program to display the system time.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    System.out.format("\nCurrent Date time: %tc%n\n", System.currentTimeMillis());
  }
}
Program 55 - Write a program to convert Celsius into Fahrenheit.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    float fahrenheit, celsius;
    celsius = 36;
    fahrenheit = (celsius * 9) / 5 + 32;
    System.out.printf("\nTemperature in fahrenheit is:  %f", fahrenheit);
  }
}
Program 56 - Write a program that will examine two inputted integers and return true if either of them is 50 or if their sum is 50.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x, y;
    System.out.print("\nEnter the value for x: ");
    x = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the value for y: ");
    y = STDIN_SCANNER.nextInt();
    if(x == 50 || y == 50 || x + y == 50) {
      System.out.print("\nTrue");
    } else {
      System.out.print("\nFalse");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 57 - Write a program that counts the even, odd, positive, and negative values among eighteen integer inputs.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x, even = 0, odd = 0, positive = 0, negative = 0;
    System.out.println("\nPlease enter 18 numbers:");
    for(int i = 0; i < 18; i++) {
    x = STDIN_SCANNER.nextInt();
      if(x > 0) {
        positive++;
      }
      if(x < 0) {
        negative++;
      }
      if(x % 2 == 0) {
        even++;
      }
      if(x % 2 != 0) {
        odd++;
      }
    }
    System.out.print("\nNumber of even values: " + even);
    System.out.print("\nNumber of odd values: " + odd);
    System.out.print("\nNumber of positive values: " + positive);
    System.out.print("\nNumber of negative values: " + negative);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 58 - Write a program to check whether the person is a senior citizen or not.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int age;
    System.out.print("Enter age: ");
    age = STDIN_SCANNER.nextInt();
    if(age >= 60) {
      System.out.print("Senior citizen");
    } else {
      System.out.print("Not a senior citizen");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 59 - Write a program that reads a student's three subject scores (0-100) and computes the average of those scores.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    float score, totalScore = 0;
    int subject = 0;
    System.out.println("Enter three subject scores (0-100):");
    while(subject != 3) {
      score = STDIN_SCANNER.nextFloat();
      if(score < 0 || score > 100) {
        System.out.println("Please enter a valid score.");
      } else {
        totalScore += score;
        subject++;
      }
    }
    System.out.printf("Average score = %.2f\n", totalScore / 3);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 60 - Write a program to find the size of an array.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    int[] num = {11, 22, 33, 44, 55, 66};
    int n = (int)num.length;
    System.out.println("Size of the array is: " + n);
  }
}
Program 61 - Write a program that prints a sequence from 1 to a given integer, inserts a plus sign between these numbers, and then removes the plus sign at the end of the sequence.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x, i;
    System.out.println("\nEnter a integer: ");
    x = STDIN_SCANNER.nextInt();
    if(x > 0) {
      System.out.println("Sequence from 1 to " + x + ":");
      for(i = 1; i < x; i++) {
        System.out.print(i + "+");
      }
      System.out.println(i);
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 62 - Write a program to verify whether a triangle's three sides form a right angled triangle or not.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int a, b, c;
    System.out.println("Enter the three sides of a triangle: ");
    a = STDIN_SCANNER.nextInt();
    b = STDIN_SCANNER.nextInt();
    c = STDIN_SCANNER.nextInt();
    if(a * a + b * b == c * c || a * a + c * c == b * b || b * b + c * c == a * a) {
      System.out.println("Triangle's three sides form a right angled triangle.");
    } else {
      System.out.println("Triangle's three sides does not form a right angled triangle.");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 63 - Write a program that will find the second-largest number among the user's input of three numbers.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int a, b, c;
    System.out.print("\nEnter the first number: ");
    a = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the second number: ");
    b = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the third number: ");
    c = STDIN_SCANNER.nextInt();
    if(a > b && a > c) {
      if(b > c) {
        System.out.print("\n" + b + " is second largest number among three numbers");
      } else {
        System.out.print("\n" + c + " is second largest number among three numbers");
      }
    } else if(b > c && b > a) {
      if(c > a) {
        System.out.print("\n" + c + " is second largest number among three numbers");
      } else {
            System.out.print("\n" + a + " is second largest number among three numbers");
      }
    } else if(a > b) {
         System.out.print("\n" + a + " is second largest number among three numbers");
      } else {
        System.out.print("\n" + b + " is second largest number among three numbers");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 64 - Write a program to calculate the sum of the two given integer values. Return three times the sum of the two values if they are equal.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    System.out.print(myfunc(3, 5));
    System.out.print("\n" + myfunc(6, 6));
  }
  public static int myfunc(int a, int b) {
    return a == b ? (a + b) * 3 : a + b;
  }
}
Program 65 - Write a program that accepts minutes as input, and display the total number of hours and minutes.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int mins, hrs;
    System.out.print("Input minutes: ");
    mins = STDIN_SCANNER.nextInt();
    hrs = mins / 60;
    mins = mins % 60;
    System.out.println("\n" + hrs + " Hours, " + mins + " Minutes.");
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 66 - Write a program to determine whether a positive number entered by the user is a multiple of three or five.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x;
    System.out.print("\nEnter a number: ");
    x = STDIN_SCANNER.nextInt();
    if(x % 3 == 0 || x % 5 == 0) {
      System.out.print("True");
    } else {
      System.out.print("False");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 67 - Write a program to verify whether one of the two entered integers falls within the range of 100 to 200 included.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x, y;
    System.out.print("\nEnter the value for x: ");
    x = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the value for y: ");
    y = STDIN_SCANNER.nextInt();
    if(x >= 100 && x <= 200 || y >= 100 && y <= 200) {
      System.out.print("True");
    } else {
      System.out.print("False");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 68 - Write a program to determine which of the two given integers is closest to the value 100. If the two numbers are equal, return 0.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    System.out.print(myfunc(86, 99));
    System.out.print("\n" + myfunc(55, 55));
    System.out.print("\n" + myfunc(65, 80));
  }

  public static int myfunc(int a, int b) {
    int x = Math.abs(a - 100);
    int y = Math.abs(b - 100);
    return x == y ? 0 : (x < y ? a : b);
  }
}
Program 69 - Write a program to determine whether a positive number entered by the user is a multiple of three or five, but not both.
Solution: 
import java.util.Scanner;
public class MyClass {
  public static void main(String[] args) {
    int x;
    System.out.print("\nEnter a number: ");
    x = STDIN_SCANNER.nextInt();
    if(x % 3 == 0 ^ x % 5 == 0) {
      System.out.print("True");
    } else {
      System.out.print("False");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 70 - Write a program to determine whether two entered non-negative numbers have the same last digit.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x, y;
    System.out.print("\nEnter the value for x: ");
    x = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the value for y: ");
    y = STDIN_SCANNER.nextInt();
    if(Math.abs(x % 10) == Math.abs(y % 10)) {
      System.out.print("True");
    } else {
      System.out.print("False");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 71 - Write a program to determine whether a given non-negative number is a multiple of 12 or it is one more than a multiple of 12.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    int x = 43;
    if(x % 12 == 0 || x % 12 == 1) {
      System.out.print("True");
    } else {
      System.out.print("False");
    }
  }
}
Program 72 - Write a program that accepts two integers and returns true when one of them equals 6, or when their sum or difference equals 6.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x, y;
    System.out.print("\nEnter the value for x: ");
    x = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the value for y: ");
    y = STDIN_SCANNER.nextInt();
    if(x == 6 || y == 6 || x + y == 6 || Math.abs(x - y) == 6) {
      System.out.print("True");
    } else {
      System.out.print("False");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 73 - Write a program to check whether it is possible to add two integers to get the third integer from three entered integers.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x, y, z;
    System.out.print("\nEnter the value for x: ");
    x = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the value for y: ");
    y = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the value for z: ");
    z = STDIN_SCANNER.nextInt();
    if(x == y + z || y == x + z || z == x + y) {
      System.out.print("True");
    } else {
      System.out.print("False");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 74 - Write a program that converts kilometers per hour to miles per hour.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    float kmph;
    System.out.print("Enter kilometers per hour: ");
    kmph = STDIN_SCANNER.nextFloat();
    System.out.printf("\n%f miles per hour", kmph * 0.6213712);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 75 - Write a program to calculate area of an ellipse.
Solution: 
import java.util.Scanner;

public class MyClass {
  public final static double PI = 3.141592;
  public static void main(String[] args) {
    float major, minor;
    System.out.print("\nEnter length of major axis: ");
    major = STDIN_SCANNER.nextFloat();
    System.out.print("\nEnter length of minor axis: ");
    minor = STDIN_SCANNER.nextFloat();
    System.out.printf("\nArea of an ellipse = %.4f", PI * major * minor);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 76 - Write a program to calculate the sum of three given integers. Return the third value if the first two values are equal.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    System.out.print("\n" + myfunc(11, 11, 11));
    System.out.print("\n" + myfunc(11, 11, 16));
    System.out.print("\n" + myfunc(18, 15, 10));
  }

  public static int myfunc(int a, int b, int c) {
    if(a == b && b == c) {
      return 0;
    }
    if(a == b) {
      return c;
    }
    if(a == c) {
      return b;
    }
    if(b == c) {
      return a;
    } else {
      return a + b + c;
    }
  }
}
Program 77 - Write a program to convert bytes to kilobytes.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    double bytes;
    System.out.print("\nEnter number of bytes: ");
    bytes = STDIN_SCANNER.nextDouble();
    System.out.printf("\nKilobytes: %.2f", bytes / 1024);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 78 - Write a program to convert megabytes to kilobytes.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    double megabytes, kilobytes;
    System.out.print("\nInput the amount of megabytes to convert: ");
    megabytes = STDIN_SCANNER.nextDouble();
    kilobytes = megabytes * 1_024;
    System.out.printf("\nThere are %f kilobytes in %f megabytes.", kilobytes, megabytes);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 79 - Write a program to count the number of even elements in an integer array.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int[] array = new int[1000];
    int arrSize, even = 0;
    System.out.print("Input the size of the array: ");
    arrSize = STDIN_SCANNER.nextInt();
    System.out.println("Enter the elements in array: ");
    for(int i = 0; i < arrSize; i++) {
      array[i] = STDIN_SCANNER.nextInt();
    }

    for(int i = 0; i < arrSize; i++) {
      if(array[i] % 2 == 0) {
        even++;
      }
    }
    System.out.print("Number of even elements: " + even);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 80 - Write a program to count the number of odd elements in an integer array.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int[] array = new int[1000];
    int arrSize, odd = 0;
    System.out.print("Input the size of the array: ");
    arrSize = STDIN_SCANNER.nextInt();
    System.out.println("Enter the elements in array: ");
    for(int i = 0; i < arrSize; i++) {
      array[i] = STDIN_SCANNER.nextInt();
    }

    for(int i = 0; i < arrSize; i++) {
      if(array[i] % 2 != 0) {
        odd++;
      }
    }
    System.out.print("Number of odd elements: " + odd);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 81- Write a program that will accept two integers and determine whether or not they are equal.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x, y;
    System.out.println("Input the values for x and y: ");
    x = STDIN_SCANNER.nextInt();
    y = STDIN_SCANNER.nextInt();
    if(x == y) {
      System.out.println("x and y are equal");
    } else {
      System.out.println("x and y are not equal");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 82 - Write a program to find the third angle of a triangle if two angles are given.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int angle1, angle2;
    System.out.print("\nEnter the first angle of the triangle: ");
    angle1 = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the second angle of the triangle: ");
    angle2 = STDIN_SCANNER.nextInt();
    System.out.print("\nThird angle of the triangle is:  " + (180 - (angle1 + angle2)));
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 83 - Write a program to determine whether a particular year is a leap year or not.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int year;
    System.out.print("Enter the year: ");
    year = STDIN_SCANNER.nextInt();
    if(year % 400 == 0) {
      System.out.print("\n" + year + " is a leap year.");
    } else if(year % 100 == 0) {
      System.out.print("\n" + year + " is a not leap year.");
    } else if(year % 4 == 0) {
      System.out.print("\n" + year + " is a leap year.");
    } else {
      System.out.print("\n" + year + " is not a leap year.");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 84 - Write a program that reads the candidate's age and determine a candidate's eligibility to cast his own vote.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int age;
    System.out.print("\nEnter the age of the candidate: ");
    age = STDIN_SCANNER.nextInt();
    if(age < 18) {
      System.out.print("\nWe apologize, but the candidate is not able to cast his vote.");
      System.out.print("\nAfter " + (18 - age) + " year, the candidate would be able to cast his vote.");
    } else {
      System.out.println("Congratulation! the candidate is qualified to cast his vote.");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 85 - Write a program to Convert Yard to Foot.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    float yard;
    System.out.print("\nEnter the Length in Yard : ");
    yard = STDIN_SCANNER.nextFloat();
    System.out.printf("\n%f Yard in Foot is: %f", yard, 3 * yard);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 86 - Write a program to convert gigabytes to megabytes.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    double gigabytes, megabytes;
    System.out.print("\nInput the amount of gigabytes to convert: ");
    gigabytes = STDIN_SCANNER.nextDouble();
    megabytes = gigabytes * 1_024;
    System.out.printf("\nThere are %f megabytes in %f gigabytes.", megabytes, gigabytes);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 87 - Write a program to Convert Kilogram to Pounds.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    float kg, lbs;
    System.out.print("\nEnter Weight in Kilogram: ");
    kg = STDIN_SCANNER.nextFloat();
    lbs = (float)(kg * 2.20462);
    System.out.printf("\n%f Kg = %f Pounds", kg, lbs);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 88 - Write a program to Convert Kilogram to Ounce.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    float kg, ounce;
    System.out.print("\nEnter Weight in Kilogram: ");
    kg = STDIN_SCANNER.nextFloat();
    ounce = (float)(kg * 35.274);
    System.out.printf("\n%f Kg = %f Ounce", kg, ounce);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 89 - Write a program to Convert Pounds to Grams.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    float pound, gram;
    System.out.print("\nEnter Weight in Pounds: ");
    pound = STDIN_SCANNER.nextFloat();
    gram = (float)(pound * 453.592);
    System.out.printf("\n%f Pound = %f Grams", pound, gram);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 90 - Write a program to verify whether a triangle is valid or not using angles.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int angle1, angle2, angle3, sum;
    System.out.print("\nEnter the first angle of the triangle: ");
    angle1 = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the second angle of the triangle: ");
    angle2 = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the third angle of the triangle: ");
    angle3 = STDIN_SCANNER.nextInt();
    sum = angle1 + angle2 + angle3;
    if(sum == 180) {
      System.out.print("\nThe triangle is valid.");
    } else {
      System.out.print("\nThe triangle is not valid.");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 91 - Write a program to add the digits of a two-digit number that is entered by the user.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x, y, sum = 0;
    System.out.print("\nEnter a two-digit number: ");
    x = STDIN_SCANNER.nextInt();
    y = x;
    while(y != 0) {
      sum = sum + y % 10;
      y = y / 10;
    }
    System.out.print("\nSum of digits of " + x + " is: " + sum);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 92 - Write a program to verify if a character you entered is a vowel or a consonant.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    System.out.println("Enter a alphabet: ");
    char ch = scanner.next().charAt(0);
    if(ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u' ||
      ch == 'A' || ch == 'E' || ch == 'I' || ch == 'O' || ch == 'U' ) {
      System.out.println(ch + " is vowel");
    }
    else {
      System.out.println(ch + " is consonant");
    }
  }
}
Program 93 - Write a program to find factorial of a number.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int fact = 1, num;
    System.out.print("\nEnter a number: ");
    num = STDIN_SCANNER.nextInt();
    for(int i = 1; i <= num; i++) {
      fact = fact * i;
    }
    System.out.print("\nFactorial of " + num + " is: " + fact);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 94 - Write a program to print number of days in a month.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int[] x = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
    int m;
    System.out.print("\nEnter the month number: ");
    m = STDIN_SCANNER.nextInt();
    if(m > 12 || m < 1) {
      System.out.print("Invalid input");
    } else if(m == 2) {
      System.out.print("\nNumber of days in month 2 is either 29 or 28");
    } else {
      System.out.print("\nNumber of days in month " + m + " is " + x[m - 1]);
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 95 - Write a program to concatenate multiple strings.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    String x = "Stephen";  
    String y = "-William";  
    String z = "-Hawking";  
    String c = x.concat(y).concat(z);  
    System.out.println(c);  
  }
}
Program 96 - Write a program to find maximum between two numbers.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int a, b;
    System.out.println("Enter two numbers: ");
    a = STDIN_SCANNER.nextInt();
    b = STDIN_SCANNER.nextInt();
    if(a > b) {
      System.out.print("\n" + a + " is a maximum number");
    } else {
      System.out.print("\n" + b + " is a maximum number");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}

public class MyClass {
  public static void main(String args[]) {
    double a = 15.143;
    double b = 15.656;
    System.out.println(Math.max(a, b));
  }
}
Program 97 - Write a program to compare two strings.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    String x = "Albert";
    String y = "Albert";
    if(x == y) {
        System.out.println("The 2 strings are equal.");
    }
    else {
        System.out.println("The 2 strings are not equal.");
    }
  }
}

public class MyClass {
  public static void main(String[] args) {
    String x = "Albert";
    String y = "Albert";
    if(x.equals(y)) {
        System.out.println("The 2 strings are equal.");
    }
    else {
        System.out.println("The 2 strings are not equal.");
    }
  }
}
Program 98 - Write a program to convert the upper case string to lower case string.
Solution: 
public class MyClass {
  public static void main(String args[]) {
    String x = new String("ALBERT EINSTEIN");
    System.out.println(x.toLowerCase());
  }
}
Program 99 - Write a program to find the quotient and remainder of a entered dividend and divisor.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int dividend, divisor;
    System.out.print("\nEnter dividend: ");
    dividend = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter divisor: ");
    divisor = STDIN_SCANNER.nextInt();
    System.out.println("\nQuotient = " + (dividend / divisor));
    System.out.print("\nRemainder = " + (dividend % divisor));
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 100 - Write a program to determine the Size of int, float, double and char.
Solution: 
public class MyClass {
  public static void main (String[] args) {
    System.out.println("Size of int is: " + (Integer.SIZE/8) + " bytes.");
    System.out.println("Size of char is: " + (Character.SIZE/8) + " bytes.");
    System.out.println("Size of float is: " + (Float.SIZE/8) + " bytes.");
    System.out.println("Size of double is: " + (Double.SIZE/8) + " bytes.");
  }
}
Program 101 - Write a program to promt user for 4 times password check.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    String password = "123";
    String inputPass;
    Scanner input = new Scanner(System.in);
    System.out.println("Enter Your Password: ");
    inputPass = input.nextLine();
    if (inputPass.equals(password)) {
      System.out.println("Welcome User!");
    }
    else {
      for(int i = 0; i < 3; i++) {
      System.out.println("Enter Your Password:");
      inputPass = input.nextLine();
    }
    System.out.println("Access Denied! Try again");
    }
  }
}
Program 102 - Write a program to find absolute value of a number.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int num;
    System.out.println("Input a positive or negative number: ");
    num = STDIN_SCANNER.nextInt();
    System.out.println("\nAbsolute value of |" + num + "| is " + Math.abs(num));
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}

public class MyClass {
  public static void main(String args[]) {
    int x = 820;
    int y = -985;
    float z = -8.1f;
    System.out.printf( "Absolute Value of x: %d \n", Math.abs(x) );
    System.out.printf( "Absolute Value of y: %d \n", Math.abs(y) );
    System.out.printf( "Absolute Value of z: %f \n", Math.abs(z) );
  }
}
Program 103 - Write a program that will accept a person's height in cm and classify the person based on it.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    float ht;
    System.out.print("\nEnter the height (in cm): ");
    ht = STDIN_SCANNER.nextFloat();
    if(ht < 150.0) {
      System.out.println("Dwarf.");
    } else if(ht >= 150.0 && ht < 165.0) {
      System.out.println("Average Height.");
    } else if(ht >= 165.0 && ht <= 195.0) {
      System.out.println("Taller.");
    } else {
      System.out.println("Abnormal height.");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 104 - Write a program to calculate the area of different geometric shapes using switch statements.
Solution: 
import java.util.Scanner;

public class MyClass {
    public static void main(String[] args) {
    int choice;
    float r, l, w, b, h;
    System.out.print("\nEnter 1 for area of circle: ");
    System.out.print("\nEnter 2 for area of rectangle: ");
    System.out.print("\nEnter 3 for area of triangle: ");
    System.out.print("\nEnter your choice : ");
    choice = STDIN_SCANNER.nextInt();

    switch(choice) {
      case 1:
      System.out.print("Enter the radius of the circle: ");
      r = STDIN_SCANNER.nextFloat();
      System.out.printf("\nArea of a circle is: %f", 3.14 * r * r);
      break;
      case 2:
      System.out.println("Enter the length and width of the rectangle: ");
      l = STDIN_SCANNER.nextFloat();
      w = STDIN_SCANNER.nextFloat();
      System.out.printf("\nArea of a rectangle is: %f", l * w);
      break;
      case 3:
      System.out.println("Enter the base and height of the triangle: ");
      b = STDIN_SCANNER.nextFloat();
      h = STDIN_SCANNER.nextFloat();
      System.out.printf("\nArea of a triangle is: %f", 0.5 * b * h);
      break;
      default:
      System.out.print("\nPlease enter a number from 1 to 3.");
      break;
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 105 - Write a program to accept a character from the keyboard and print "Yes" if it is equal to y. Otherwise print "No".
Solution: 
public class MyClass {
  public static void main(String[] args) throws Exception {
    char ch;
    System.out.println("Enter a character: ");
    ch = (char)System.in.read();
    if(ch == 'y' || ch == 'Y') {
      System.out.println("Yes\n");
    }
    else {
      System.out.println("No\n");
    }     
  }
}
Program 106 - Write a program that uses bitwise operators to multiply an entered value by four.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    long x, y;
    System.out.print("Enter a integer: ");
    x = STDIN_SCANNER.nextLong();
    y = x;
    x = x << 2;
    System.out.println(y + " x 4 = " + x);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 107 - Write a program to check whether a number entered by the user is power of 2 or not.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x;
    System.out.print("Enter a number: ");
    x = STDIN_SCANNER.nextInt();
    if(x != 0 && (x & x - 1) == 0) {
      System.out.print("\n" + x + " is a power of 2");
    } else {
      System.out.print("\n" + x + " is not a power of 2");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 108 - Write a program to determine whether a triangle is scalene, isosceles, or equilateral.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int side1, side2, side3;
    System.out.print("\nEnter the first side of the triangle: ");
    side1 = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the second side of the triangle: ");
    side2 = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the third side of the triangle: ");
    side3 = STDIN_SCANNER.nextInt();
    if(side1 == side2 && side2 == side3) {
      System.out.print("\nThe given Triangle is equilateral.");
    } else if(side1 == side2 || side2 == side3 || side3 == side1) {
      System.out.print("\nThe given Triangle is isosceles.");
    } else {
      System.out.print("\nThe given Triangle is scalene.");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 109 - Write a program to print ASCII values of all the letters of the English alphabet from A to Z.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    for(int i = 'A'; i <= 'Z'; i++) {
      System.out.println("ASCII value of " + ((char)Byte.toUnsignedInt((byte)i)) + " = " + i);
    }
  }
}
Program 110 - Write a program to find sum of even numbers between 1 to n.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int num, sum = 0;
    System.out.print("Enter a number: ");
    num = STDIN_SCANNER.nextInt();
    for(int i = 2; i <= num; i = i + 2) {
      sum = sum + i;
    }
    System.out.print("\nSum of all even number between 1 to " + num + " is: " + sum);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 111 - WWrite a program to find sum of odd numbers between 1 to n.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int num, sum = 0;
    System.out.print("Enter a number: ");
    num = STDIN_SCANNER.nextInt();
    for(int i = 1; i <= num; i = i + 2) {
      sum = sum + i;
    }
    System.out.print("\nSum of all odd number between 1 to " + num + " is: " + sum);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 112 - WWrite a program that accepts an integer (x) and computes the value of x+xx+xxx.
Solution: 
import java.util.Scanner;
public class MyClass {
  public static void main(String[] args) {
    int x;
    Scanner in = new Scanner(System.in);
    System.out.print("Enter a number: ");
    x = in .nextInt();
    System.out.printf("%d + %d%d  + %d%d%d\n", x, x, x, x, x, x);
  }
}
Program 113 - WWrite a program that allows you to enter the cost price and the selling price of a product and calculate profit or loss.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int cp, sp;
    System.out.print("\nInput Cost Price: ");
    cp = STDIN_SCANNER.nextInt();
    System.out.print("\nInput Selling Price: ");
    sp = STDIN_SCANNER.nextInt();
    if(sp > cp) {
    System.out.print("Profit = " + (sp - cp));
    } else if(cp > sp) {
    System.out.print("Loss = " + (cp - sp));
    } else {
    System.out.print("No Profit No Loss.");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 114 - WWrite a program that display the pattern like a right angle triangle using an asterisk.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int rows;
    System.out.print("Input the number of rows: ");
    rows = STDIN_SCANNER.nextInt();
    for(int x = 1; x <= rows; x++) {
    for(int y = 1; y <= x; y++) {
    System.out.print("*");
    }
    System.out.println();
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 115 - WWrite a program that display the pattern like a right angle triangle using a number.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int rows;
    System.out.print("Input the number of rows: ");
    rows = STDIN_SCANNER.nextInt();
    for(int x = 1; x <= rows; x++) {
      for(int y = 1; y <= x; y++) {
        System.out.print(y);
      }
      System.out.println();
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 116 - WWrite a program to determine the number and sum of all integers between 50 and 100 which are divisible by 2.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    int sum = 0;
    System.out.println("Numbers between 50 and 100, divisible by 2: ");
    for(int x = 51; x < 100; x++) {
      if(x % 2 == 0) {
        System.out.printf("%5d", x);
          sum += x;
      }
    }
  System.out.print("\nThe sum: " + sum);
  }
}
Program 117 - WWrite a program that uses the function to determine whether a entered number is even or odd.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static int myfunc(int x) {
    return x & 1;
  }

  public static void main(String[] args) {
    int x;
    System.out.print("Enter any number: ");
    x = STDIN_SCANNER.nextInt();
    if(myfunc(x) != 0) {
      System.out.print("\nThe number you entered is odd.");
    } else {
      System.out.print("\nThe number you entered is even.");
    }
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 118 - WWrite a program to find square root of a entered number.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x;
    System.out.print("Enter any number: ");
    x = STDIN_SCANNER.nextInt();
    System.out.printf("Square root of %d is %.2f", x, Math.sqrt(x));
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 119 - WWrite a program to find power of a entered number using library function.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x, y;
    System.out.print("\nEnter the value for x: ");
    x = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the value for y: ");
    y = STDIN_SCANNER.nextInt();
    System.out.print("\n" + x + "^" + y + " = " + ((long)Math.pow(x, y)));
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 120 - WWrite a program to read 10 numbers from the keyboard and find their sum and average.
Solution: 
import java.util.Scanner;
public class MyClass {
  public static void main(String [] args) {
    int N1, N2, N3, N4, N5, N6, N7, N8, N9, N10, sum;
    float X;
    Scanner scan = new Scanner(System.in);
    System.out.println("Enter any ten Numbers: ");
    N1 = scan.nextInt();
    N2 = scan.nextInt();
    N3 = scan.nextInt();
    N4 = scan.nextInt();
    N5 = scan.nextInt();
    N6 = scan.nextInt();
    N7 = scan.nextInt();
    N8 = scan.nextInt();
    N9 = scan.nextInt();
    N10 = scan.nextInt();
    sum = N1 + N2 + N3 + N4 + N5 + N6 + N7 + N8 + N9 + N10;
    X = sum /10;
    System.out.println("The sum of 10 numbers = " + sum);
    System.out.println("The average of 10 numbers = " + X);
  }
}
Program 121 - Write a program to determine whether the given character is an alphanumeric character or not.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    String x="abc123", y="abc.com";
    System.out.println(x.matches("[a-zA-Z0-9]+"));
    System.out.println(y.matches("[a-zA-Z0-9]+"));
  }
}
Program 122 - Write a program to illustrate try-catch statement.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    try {
      int[] num = {1, 2, 3};
      System.out.println(num[3]);
    } catch (Exception e) {
    System.out.println("Something went wrong.");
    }
  }
}
Program 123 - Write a program to remove all whitespaces from a given string.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    String x = "T    his is b  ett     er.";
    x = x.replaceAll("\\s", "");
    System.out.println(x);
  }
}
Program 124 - Write a program to get current working directory.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    String path = System.getProperty("user.dir");
    System.out.println("Current Working Directory: " + path);
  }
}
Program 125 - Write a program to split a sentence into words.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    String x = "Hai this is Alan";
    String [] y = x. split(" ", 3);
    for(String i : y)
    System. out. println(i);
  }
}
Program 126 - Write a program to replace all occurrences of 'a' to 'e' in a string.
Solution: 
public class MyClass {  
  public static void main(String args[]){  
    String x="Java is a powerful general-purpose programming language.";  
    String replaceString=x.replace('a','e'); 
    System.out.println(replaceString);      
  }   
}
Program 127 - Write a program to check if the given string is empty or not.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    String a="";  
    String b="Java";  
    System.out.println(a.isEmpty());  
    System.out.println(b.isEmpty());  
  }
}
Program 128 - Write a program to illustrate .join() method.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    String a=String.join("-","Java","Programming");  
    System.out.println(a);  
  }
}
Program 129 - Write a program to calculate surface area of cube.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int side;
    long area;
    System.out.print("\nEnter the side of cube: ");
    side = STDIN_SCANNER.nextInt();
    area = 6 * side * side;
    System.out.print("\nThe surface area of cube is: " + area);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 130 - Write a program to subtract 2 numbers without using subtraction operator.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    int x = 6, y = 3;
    System.out.print(x + ~y + 1);
  }
}
Program 131 - Write a program to add 2 numbers without using addition operator.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    int x = 6, y = 3;
    System.out.print(x - ~y - 1);
  }
}
Program 132 - Write a program to multiply a number by 2 without using multiplication operator.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    int x = 2;
    System.out.print(x << 1);
  }
}
Program 133 - Write a program to divide a number by 2 without using division operator.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    int x = 12;
    System.out.print(x >> 1);
  }
}
Program 134 - Write a program to calculate volume of sphere.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int radius;
    float PI = 3.141592f;
    System.out.print("\nEnter the radius of sphere: ");
    radius = STDIN_SCANNER.nextInt();
    float volume = (4 / 3) * (PI * radius * radius * radius);
    System.out.printf("\nThe volume of sphere is: %f", volume);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 135 - Write a program to calculate volume of ellipsoid.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int r1, r2, r3;
    float PI = 3.141592f;
    System.out.print("\nEnter the radius of the ellipsoid of axis 1: ");
    r1 = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the radius of the ellipsoid of axis 2: ");
    r2 = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the radius of the ellipsoid of axis 3: ");
    r3 = STDIN_SCANNER.nextInt();
    float volume = (4 / 3) * (PI * r1 * r2 * r3);
    System.out.printf("\nThe volume of ellipsoid is: %f", volume);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 136 - Write a program that uses a for loop to determine power of a number entered by the user.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int x, y;
    long power = 1;
    System.out.print("\nEnter the value for x: ");
    x = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the value for y: ");
    y = STDIN_SCANNER.nextInt();
    for(int i = 1; i <= y; i++) {
      power = power * x;
    }
    System.out.print(x + " ^ " + y + " = " + power);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 137 - Write a program to read three numbers and find average of numbers.
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int a, b, c;
    float avg;
    System.out.print("\nEnter the first number: ");
    a = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the second number: ");
    b = STDIN_SCANNER.nextInt();
    System.out.print("\nEnter the third number: ");
    c = STDIN_SCANNER.nextInt();
    avg = (float)(a + b + c / 3.0);
    System.out.printf("\nAverage of three numbers is: %f", avg);
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 138 - Write a program to read integer "n" and print first three powers (n1, n2, n3).
Solution: 
import java.util.Scanner;

public class MyClass {
  public static void main(String[] args) {
    int n;
    System.out.print("\nEnter a number: ");
    n = STDIN_SCANNER.nextInt();
    System.out.printf("%f, %f, %f", Math.pow(n, 1), Math.pow(n, 2), Math.pow(n, 3));
  }
  public final static Scanner STDIN_SCANNER = new Scanner(System.in);
}
Program 139 - Write a program to search the substring in a given string.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    String name="Java is a powerful general-purpose programming language";  
    System.out.println(name.contains("Java"));  
    System.out.println(name.contains("programming"));  
    System.out.println(name.contains("language"));  
  }
}
Program 140 - Write a program to check if the string ends with a given suffix.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    String a="Java Programming";  
    System.out.println(a.endsWith("g"));  
  }
}
Program 141 - Write a program to check if the string starts with the given prefix.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    String a="Java Programming";    
    System.out.println(a.startsWith("j"));    
    System.out.println(a.startsWith("J"));    
  }
}
Program 142 - Write a program to check whether a character is alphabet, digit or special character.
Solution: 
import java.util.Scanner;
public class MyClass {
  public static void main(String[] args) {
    char ch;
    Scanner x=new Scanner(System.in);
    System.out.print("Enter a character: ");
    ch=x.next().charAt(0);
    if((ch>='a'&&ch<='z')||(ch>='A'&&ch<='Z')) {
      System.out.println(ch+" is Alphabet.");
    }
    else if(ch>='0'&&ch<='9') {
      System.out.println(ch+" is Digit.");
    }
    else {
      System.out.println(ch+" is Special Character.");
    }
  }
}
Program 143 - Write a program to Check whether Java is installed on your computer.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    System.out.println("\nJava Version: "+System.getProperty("java.version"));
    System.out.println("Java Runtime Version: "+System.getProperty("java.runtime.version"));
    System.out.println("Java Home: "+System.getProperty("java.home"));
    System.out.println("Java Vendor: "+System.getProperty("java.vendor"));
    System.out.println("Java Vendor URL: "+System.getProperty("java.vendor.url"));
    System.out.println("Java Class Path: "+System.getProperty("java.class.path")+"\n");
  }
}
Program 144 - Write a program to Check whether Java is installed on your computer.
Solution: 
public class MyClass {
  public static void main(String[] args) {
    System.out.println("\nJava Version: "+System.getProperty("java.version"));
    System.out.println("Java Runtime Version: "+System.getProperty("java.runtime.version"));
    System.out.println("Java Home: "+System.getProperty("java.home"));
    System.out.println("Java Vendor: "+System.getProperty("java.vendor"));
    System.out.println("Java Vendor URL: "+System.getProperty("java.vendor.url"));
    System.out.println("Java Class Path: "+System.getProperty("java.class.path")+"\n");
  }
}
Program 145 - Write a program to get the current system environment and system properties.
Solution: 
import java.lang.*;
public class Main {
  public static void main(String[] args) {
    System.out.println("\nCurrent system environment:");
    System.out.println(System.getenv());   
    System.out.println("\n\nCurrent system properties:");
    System.out.println(System.getProperties()); 
  }
}
Program 146 - Write a program to measure how long code takes to execute in nanoseconds.
Solution: 
import java.lang.*;
public class Main {
  public static void main(String[] args) {    
    long startTime = System.nanoTime(); 
    int i;
    System.out.println ("The first 5 natural numbers are:\n");
    for (i=1;i<=5;i++) {      
      System.out.println(i);
    }
    long estimatedTime = System.nanoTime() - startTime;
    System.out.println("Estimated time (in nanoseconds) to get the first 5 natural numbers: "+estimatedTime);
  }
}
Program 147 - Write a program to replace the spaces of a string with a specific character.
Solution: 
public class MyClass {    
  public static void main(String[] args) {    
    String a = "Java Programming";    
    char ch = '-';    
    a = a.replace(' ', ch);    
    System.out.println("String after replacing spaces with the character '-': ");    
    System.out.println(a);    
  }    
}
Program 148 - Write a program to count the total number of punctuations in a given string.
Solution: e> public class Main { public static void main (String args[]) { int count = 0; String str = "Logic will get you from A to Z; imagination will get you everywhere."; for(int i = 0; i < str.length(); i++) { if(str.charAt(i) == '!' || str.charAt(i) == ',' || str.charAt(i) == ';' || str.charAt(i) == '.' || str.charAt(i) == '?' || str.charAt(i) == '-' || str.charAt(i) == '\'' || str.charAt(i) == '\"' || str.charAt(i) == ':') { count++; } } System.out.println("The total number of punctuations in a given string is: " +count); } }
Program 149 - Write a program to convert Decimal to Hexadecimal.
Solution: 
public class MyClass {  
  public static void main(String args[]){  
    System.out.println(Integer.toHexString(10));  
    System.out.println(Integer.toHexString(15));  
    System.out.println(Integer.toHexString(289));  
  }
}
Program 150 - Write a program to convert Decimal to Octal.
Solution: 
public class MyClass {  
  public static void main(String args[]){  
    System.out.println(Integer.toOctalString(8));  
    System.out.println(Integer.toOctalString(19));  
    System.out.println(Integer.toOctalString(81));
  }
}
Program 151 - Write a program to convert Decimal to Binary.
Solution: 
public class MyClass {  
  public static void main(String args[]){  
    System.out.println(Integer.toBinaryString(10));  
    System.out.println(Integer.toBinaryString(21));  
    System.out.println(Integer.toBinaryString(31));  
  }
}
Program 152 - Write a program to convert Binary to Decimal.
Solution: 
public class MyClass {  
  public static void main(String args[]){  
    String a="1010";  
    int decimal=Integer.parseInt(a,2);  
    System.out.println(decimal);  
  }
}
Program 153 - Write a program to convert Hexadecimal to Decimal.
Solution: 
public class MyClass {  
  public static void main(String args[]){  
    String hex="a";  
    int decimal=Integer.parseInt(hex,16);  
    System.out.println(decimal);  
  }
}
Program 154 - Write a program to determine whether one string is a rotation of another.
Solution: 
public class MyClass {    
  public static void main(String[] args) {    
    String x = "abcde", y = "deabc";    
    if(x.length() != y.length()){    
       System.out.println("Second string is not a rotation of first string");    
    }    
    else {    
        x = x.concat(x);    
                
            if(x.indexOf(y) != -1)    
                System.out.println("Second string is a rotation of first string");    
            else    
                System.out.println("Second string is not a rotation of first string");    
    }    
  }    
}
Program 155 - Write a program to illustrate the isNaN method.
Solution: 
public class MyClass {
  public static void main(String args[]) {
            
    /* The isNaN method returns true if the value is NaN. */
            
    Float a = Float.NaN;
    Float b = 6.0f;
    System.out.println(a +" - " + a.isNaN()); 
    System.out.println(a +" - " + Float.isNaN(a)); 
    System.out.println(b +" - " + Float.isNaN(b));
  }
}
Program 156 - Write a program to illustrate the isNaN method.
Solution: 
public class MyClass {
  public static void main(String args[]) {
            
    /* The isNaN method returns true if the value is NaN. */
            
    Float a = Float.NaN;
    Float b = 6.0f;
    System.out.println(a +" - " + a.isNaN()); 
    System.out.println(a +" - " + Float.isNaN(a)); 
    System.out.println(b +" - " + Float.isNaN(b));
  }
}
Program 157 - Write a program to Design Simple Calculator.
Solution: 
import java.util.Scanner;

public class MyClass {
public static void main(String[] args) {

char operator;
Double number1, number2, result;
Scanner input = new Scanner(System.in);
System.out.println("Choose an operator: +, -, *, or /");
operator = input.next().charAt(0);

System.out.println("Enter first number:");
number1 = input.nextDouble();

System.out.println("Enter second number:");
number2 = input.nextDouble();

switch (operator) {

      case '+':
        result = number1 + number2;
        System.out.println(number1 + " + " + number2 + " = " + result);
        break;

      case '-':
        result = number1 - number2;
        System.out.println(number1 + " - " + number2 + " = " + result);
        break;
  
      case '*':
        result = number1 * number2;
        System.out.println(number1 + " * " + number2 + " = " + result);
        break;
   
      case '/':
        result = number1 / number2;
        System.out.println(number1 + " / " + number2 + " = " + result);
        break;

      default:
        System.out.println("Invalid operator!");
        break;
    }

    input.close();
  }
}
Program 158 - Write a program to print Invert Triangle.
Solution: 
public class MyClass {
  public static void main(String args[]) {
    int x = 9;
    while(x > 0) {
        for(int i=1; i<=x; i++) {
            System.out.print(" "+x+" ");
        }
    System.out.print("\n");
    x--;
    }
  }
}