ForLoops.java

public class ForLoops {

    public static void main(String[] args) {

        // for ( init ; test ; increment ) {
        //     body
        // }

        // 1) The 'init' code runs once to set things up at the very start of the loop.
        // 2) The boolean 'test' is evaluated.
        // 3) The 'body' is a series of statements.
        // 4) Finally, the 'increment' code executes just after the body.

        for (int i = 0; i < 100; i++) {
            System.out.println("i:" + i);
        }

        // 'continue' - skips to next iteration of the loop. useful to short circuit iteration in order to avoid something expensive.
        // 'break' - discontinues execution of the loop. useful if further work is unnecessary.
        
        int answer = -1;
        for (int i = Integer.MAX_VALUE; i > 0; i--) {
            if (isEven(i)) { // cheap to check
                // can't be the answer if its even, avoid expensive calc below
                continue;
            }
            if (isPrime(i)) { // comparatively expensive
                answer = i;
                // found our answer, no need to keep computing
                break;
            }
        }

        System.out.println("The first prime less than max int is " + answer);
    }

    private static boolean isEven(int i) {
        return i % 2 == 0;
    }

    private static boolean isPrime(int n) {
        for (int i = 2; i < n / 2; i++) {
            if (n % i == 0) {
                return false;
            }
        }
        return true;
    }

}