Java this and super keywords

Question

I've got a question about Java this and super keywords, let's take some examples

Firts example

import java.awt.*;

public class Main extends Frame {
        //constructor of the class 
        public Main () {
                super ("My frame");
                setSize (200,100);
                setVisible (true);
        }

        public static void main (String [] args) {
                 new Main ();
         }
}

second example

import java.awt.*;

public class Main extends Frame {
        //constructor of the class 
        public Main () {
                //here the difference from example 1    
                super ("My frame");
                super.setSize (200,100);
                super.setVisible (true);
        }

        public static void main (String [] args) {
                 new Main ();
         }
}

Which example is better and why?

Now let's take some examples about this keyword

public class Main {
        public void print () {
                System.out.println ("Hi");
        }

        public static void main (String [] args) {
                 print();
         }
}

Second example

public class Main {

        public void print () {
                System.out.println ("Hi");
        }

        public static void main (String [] args) {
                 //here the difference
                 this.print();
         }
}

Which is better and why? Thank you for your answers

Answer 1

Use super only when you really need to. If you override setSize() then you would find the second example would not call your overridden methods. This is not necessarily desired behaviour and therefore you should generally just call methods without the super prefixing operator. It's generally best to write code such that it can be extended or maintained without having to worry about whether or not some overrides will actually override from certain methods or not. Also see Vulcan's comment rendering the issue null and void.