package arraylistplay;

import java.util.ArrayList;

public class Primes {
    public static void main(String[] args) {
        ArrayList<Integer> primes = new ArrayList<>();
        //Q. why it needs a full name of the type int in the angle bracket?
        primes.add(2);
        primes.add(3);
        primes.add(5);
        primes.add(7);

        System.out.println("The size of the primes list = "  + primes.size());
        System.out.println("first prime = " + primes.get(0));
        System.out.println("last prime = " + primes.get(primes.size() - 1));
        System.out.println("last prime = " + primes.get(3));

        System.out.println("\n The initial list ...");
        for (Integer prime : primes) {
            System.out.println(prime);
            //Q. what the things in the parenthesis of for statement are?
        }

        int temp = primes.get(0);
        primes.set(0, primes.get(primes.size() -1 ));
        //Q. what the .set(); tells us about? how it works?
        primes.set(primes.size() - 1, temp);
        // I think this part has charged to make everything on the .txt file get flipped backward.

        System.out.println("\n The final list...");
        for (Integer prime : primes) {
            System.out.println(prime);
        }
        //this for loop being affected by the flipping codeSubset above.
        // So it eventually souts everything in the reverse order of the initial list.

    }
}