Java Program to check a number is prime or not using recursion


In this program, you will learn how to check a number is prime or not using recursion in java.


Some list of prime numbers : 2 3 5 7 11 13 17

Example: How to check a number is prime or not using recursion in java.

import java.util.Scanner;

class Main {
    int p = 1;


    int checkPrime(int n, int i) {
        if (n % i == 0 && i <= n/2) {
            return p = 0;
        } else if (i <= n / 2) {
            checkPrime(n, i = i + 1);
        }

        return p;
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        System.out.print("Enter a number:");
        int n = sc.nextInt();

        Main obj = new Main();
        int p = obj.checkPrime(n, 2);

        if (p == 1) {
            System.out.println("Number is prime:" + n);
        } else {
            System.out.println("Number is not prime:" + n);
        }

    }
}

Output:

Enter a number:19
Number is prime:19