kindly tell me the coding for "=" button

Question

I am writing the coding of CALCULATOR in Java.

Answer 1

If i understood you right..
For the first you need to implement the ActionListener interface.

Then add this into your method:

public void actionPerformed(ActionEvent e){
if(e.getSource() == yourButton){
// do something
}
}

And in your main method add the action to your button:

YourButton.addActionListener(this);