Strings - General Questions

What is the output of the following program?

public class Main {
    public static void main(String[] args) {
        System.out.println("apple".compareTo("banana") < 0);
    }
}

What is the output of the following program?

public class Main {
    public static void main(String[] args) {
        String s = "Mississippi";
        System.out.println(s.indexOf("ss") + " " + s.lastIndexOf("ss"));
    }
}

What is the output of the following program?

public class Main {
    public static void main(String[] args) {
        System.out.println(String.join("|", "x", "y", "z"));
    }
}

What is the output of the following program?

public class Main {
    public static void main(String[] args) {
        String s = "Programming";
        System.out.println(s.substring(3, 7) + " " + s.indexOf('g') + " " + s.charAt(0));
    }
}

What is the output of the following program?

public class Main {
    public static void main(String[] args) {
        String s = "Java";
        s.concat(" 17");
        System.out.println(s);
    }
}