Adding two chars

public class Main {
    public static void main(String[] args) {
        System.out.println('a' + 'b');
        System.out.println("" + 'a' + 'b');
        System.out.println('a' + 'b' + "");
        char c = 'A';
        System.out.println((char) (c + 2));
    }
}