Java Program to Check Whether a Number can be Expressed as Sum of Two Prime Numbers

// Importing all the required packages
import java.util.Scanner;
import java.util.*;

public class Main{
  public static void main(String[] args){
    // Scanner class for taking input  
    Scanner scn = new Scanner(System.in);
    System.out.println("Enter a number: ");
    int n = scn.nextInt();
    
    boolean isFound = false;
    
    // loop to iterate over the given input
    for (int i = 2; i <= n / 2; i++) {
      // if the boolean variable is true
      if (isPrime(i)) {
        int diff = n - i;

        if (isPrime(diff)) {
          System.out.println(n + " can be expressed as the sum of " + i + " and " + diff);
          isFound = true;
        }
      }
    }
    
    // if the boolean variable is false
    if (!isFound) {
      System.out.println(n + " cannot be expressed as the sum of two prime numbers.");
    }
  }

  // function to check whether a number is prime or not
  public static boolean isPrime(int n) {
    if (n <= 1) {
      return false;
    }
    for (int i = 2; i < n; i++) {
      if (n % i == 0) {
        return false;
      }
    }
    return true;
  }
}