Question

Write a method which takes as input an integer, returns true if the integer is prime, and returns false otherwise. Do not import anything.

If the input is negative, 0 or 1, false should be returned.

If the input x is greater than 1, you can test if it is prime (inefficiently) by checking if it is divisible by any integer from 2 up to half of x. If it is not divisible by any of these numbers, then it is prime; otherwise, it is not prime.

Your submission should also include the client that you use to test your method.

in java

Answer 1

//IsPrimeCheck.java
import java.util.Scanner;
public class IsPrimeCheck {
    // Returns true if x is prime, and false otherwise.
    public static boolean isPrime(int x) {
        if(x<2){
            return false;
        }
        else {
            for (int i = 2; i <= x/2; i++) {
                if (x % i == 0) {
                    return false;
                }
            }
            return true;
        }
    }

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        System.out.println("Please enter an integer");
        int n = scan.nextInt();
        System.out.println(isPrime(n));
    }
}