Question

Consider the Java code below, what would happen if there were no paintComponent method in JPanel class?

...

import javax.swing.JPanel;

public class ShapesJPanel extends JPanel
{

     public void paintComponent( Graphics g )
     {
       super.paintComponent( g );
       //more codes here  
     }
}

Answer 1

If that s the specific situation you re asking about then it s always there.
If you re asking in general then it won t compile.

Answer 2

It won t compile. If it was there at compile time but not at runtime, then it will throw an Error.

Answer 3

There will always be an implementation in the super class.

JPanel implements paintComponent(). So, you don t need to worry about it.

Answer 4

At compile time

The method should present in any of the class in super class hierarchy otherwise compilation will fail
The method of the class from that hierarchy ( starting from bottom) will get called

At run time

If method does not found it will throw an error

At compile time

At run time

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