Question

Check whether a number is prime number or not using recursion

Prime number is a number that is greater than 1 and divided by 1 or itself only. In other words, prime numbers can't be divided by other numbers than itself or 1. For example 2, 3, 5, 7, 11, 13, 17.... are the prime numbers.

ENTER A NUMBER:13
13 IS PRIME NUMBER

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Code

Java

Python

Java

import java.util.Scanner;

public class primeNumber
{
    public static boolean checkPrime(int n,int i)
    {
        if(n<=1)
        {
            return false;
        }

        else if(i==n)
        {
            return true;
        }

        else if(n%i==0)
        {
            return false;
        }
        else
        {
            return  checkPrime(n,(i+1));
        }
    }

    public static void main()
    {
        int num=0;
        boolean isPrime=false;
        Scanner sc=new Scanner(System.in);
        System.out.print("ENTER A NUMBER:");
        num=sc.nextInt();
        isPrime=checkPrime(num,2);
        if(isPrime==true)
        {
            System.out.println(num+" IS PRIME NUMBER");
        }
        else
        {
            System.out.println(num+" IS NOT PRIME NUMBER");
        }
    }
}

Python

def isPrime(n,i=2):
    if(n<=1):
        return False
    elif(i==n):
        return True
    elif(n%i==0):
        return False
    else:
        return isPrime(n,i+1)

#Main Method Starts from here
if(__name__=='__main__'):
    number=int(input("Enter a number:"))
    if(isPrime(number) == True):
        print(number,"IS A PRIME NUMBER")
    else:
        print(number, "IS NOT A PRIME NUMBER")