Prime Number Program in Java

Prime Number Program in Java
Prime Number Program in Java

A prime number is a natural number greater than 1 that cannot be formed by multiplying two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime because the only ways of writing it as a product, 1 × 5 or 5 × 1, involve 5 itself.


import java.util.Scanner;

public class PrimeNumber
{
    public static void main(String[] args)
    {
        // TODO code application logic here
        int n,
        i = 2;
        boolean flag = true;
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter number=");
        n = sc.nextInt();
        while (n > i)
        {
            if (n % 2 == 0)
            {
                flag = false;
                break;
            }
            i++;
        }
        if (flag)
        {
            System.out.println("Number is prime.");
        }
        else
        {
            System.out.println("Number is not prime.");
        }
    }
}

Output:

Enter number=17
Number is prime.
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Frequently Asked Questions

A prime number is a natural number greater than 1 that cannot be formed by multiplying two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime because the only ways of writing it as a product, 1 × 5 or 5 × 1, involve 5 itself.
A prime number is a natural number greater than 1 that cannot be formed by multiplying two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime because the only ways of writing it as a product, 1 × 5 or 5 × 1, involve 5 itself.