布尔返回类型的方法在main（）内部不起作用

Question

I had static method which is to find out prime number and it is working fine but the same method i am trying to keep inside main method it is throwing errors by stating illegal modifiers for parameter and void method does not return value the same code is working fine outside of main method, any one plz sugggest me why it is not working in main() . Thanks ..!!

My method

public static boolean isPrimeNumber(int number) {
        if (number == 2 || number == 3) {
            return true;
        }
        if (number % 2 == 0) {
            return false;
        }
        int sqrt = (int) Math.sqrt(number) + 1;
        for (int i = 3; i < sqrt; i += 2) {
            if (number % i == 0) {
                return false;
            }
        }
        return true;
    }

Inside main() with lot of error message inside main

Solution

Thanks Logan --- need to add methods outside main method my working code is added below

public class Squar {

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int num = scan.nextInt();
        Squar s = new Squar();
        //System.out.println(s.isPrime(num));
        scan.close();
        System.out.println("M2 "+s.isPrimeNumber(num));


    }
    public  boolean isPrimeNumber(int number) {
        if (number == 2 || number == 3) {
            return true;
        }
        if (number % 2 == 0) {
            return false;
        }
        int sqrt = (int) Math.sqrt(number) + 1;
        for (int i = 3; i < sqrt; i += 2) {
            if (number % i == 0) {
                return false;
            }
        }
        return true;
    }

}

Answer 1

You are getting this error because Java does not support nested function. You are implementing method inside other method, that is not possible. to nest methods use lambdas in java 8.

have a look at Can methods in java be nested and what is the effect? [closed]