Do....while Loop question

[Roter]

This is a pretty simple question, and Im kindof a newbie at java.
I have this prime finder, but Im not sure how to find the next greatest prime, heres the code so far

public class Prime {

    public static void main(String[] args) { 
        long N = 15;
        boolean isPrime = true;
        if (N < 2) isPrime = false;        
        for (long i = 2; i*i <= N; i++) {

            // if i divides evenly into N, N is prime, so break out of loop
            if (N % i == 0) {
                isPrime = false;
                break;
            }
        }
        do {
        	N += 1;
        } while (!isPrime);

       
        if (isPrime) System.out.println(N + " is prime");
    }
}

I was just wondering how to make the while (!isPrime) statement stop once it has found the next greatest prime. Any Help would be much appreciated

[diamonddragon]

What is that You want with

        do {
            N += 1;
        } while (!isPrime);

[Roter]

I want it to stop the search once it hits isPrime is true

[diamonddragon]

Have You considered to put that condition in for loop?

[Roter]

Sorry, Can you point me in the direction for that extra condition? I don't know quite yet what that would look like

[diamonddragon]

What is the difference between isPrime in for loop, and isPrime in while loop?

[Roter]

Nothing, Same function, The for loop checks for if its prime, I want the do while loop to find the next prime if the number N is not prime

[diamonddragon]

Is same, can You avoid using isPrime in while loop?

[Roter]

I guess, but what would that help with? its just the boolean operand, N is meant to be the prime

[diamonddragon]

Try to throw out that while loop, and say what happened?

Also, using this:

for (long i = 2; i*i <= N; i++)

You will not check prime number.
Do You know why?

[Roter]

I just replaced the program prime checker with a loop that finds next greatest prime regardless, thanks for helping though, I really appreciate it