Checking Prime with Varargs in Java


Write a Java program demonstrating a method with varargs that checks if a specific integer is prime

  • The PrimeChecker class contains a static method named isPrime that checks whether each given number is prime or not.
  • It iterates through each number in the array of numbers.
  • For each number, it first assumes it's prime (prime = true).
  • If the number is less than or equal to 1, it sets prime to false because prime numbers are greater than 1.
  • For numbers greater than 1, it iterates from 2 to num/2 and checks if num is divisible by any number other than 1 and itself.
  • If it finds such a number, it sets prime to false and breaks out of the loop.
  • After checking all numbers, it prints whether each number is prime or not.
  • In the main method, the isPrime method is called with the numbers 1, 2, 3, 4, and 5.
  • The output will show whether each number is prime or not.

Source Code

public class PrimeChecker
{
	static boolean isPrime(int... numbers)
	{
		boolean prime = true;
		for (int num : numbers)
		{
			if (num <= 1)
			{
				prime = false;
			}
			else
			{
				for (int i = 2; i <= num / 2; i++)
				{
					if (num % i == 0)
					{
						prime = false;
						break;
					}
				}
			}
			System.out.println(num + " is Prime ? " + prime);
		}
		return prime;
	}
 
	public static void main(String[] args)
	{
		isPrime(1, 2, 3, 4, 5);
	}
}

Output

1 is Prime ? false
2 is Prime ? false
3 is Prime ? false
4 is Prime ? false
5 is Prime ? false

Example Programs