Strings - General Questions

What is the output of the following program?

public class Main {
    public static void main(String[] args) {
        System.out.println("ha".repeat(3));
    }
}

What is the output of the following program?

public class Main {
    public static void main(String[] args) {
        StringBuilder sb = new StringBuilder("abc");
        sb.reverse().append("!");
        System.out.println(sb);
    }
}

What is the output of the following program?

public class Main {
    public static void main(String[] args) {
        String a = "hello";
        String b = new String("hello");
        System.out.println((a == b) + " " + a.equals(b));
    }
}

What is the output of the following program?

public class Main {
    public static void main(String[] args) {
        StringBuilder sb = new StringBuilder("abc");
        sb.append("d").reverse();
        System.out.println(sb);
    }
}

What is the output of the following program?

public class Main {
    public static void main(String[] args) {
        System.out.println(String.join("-", "a", "b", "c") + " " + "ab".repeat(2));
    }
}