Doing Add and Substract
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
/**
* Delegation Model: we clicked on button:
* but another object did the job of adding or substracting
*/
class mathsss_demo extends JFrame implements ActionListener{
JLabel n1,n2,ans;
JTextField jtn1,jtn2;
JButton btnadd,btnsub;
public mathsss_demo(){
n1 = new JLabel("Enter a num");
n2 = new JLabel("Enter a num");
ans = new JLabel("");
ans.setBounds(20,80,150,20);
jtn1 = new JTextField();
jtn2 = new JTextField();
btnadd = new JButton("Add");
btnsub = new JButton("Sub");
setLayout(null);//we are not taking any pre-defined setLayout
n1.setBounds(20,20,150,20);//x,y,width,height
jtn1.setBounds(180,20,150,20);
n2.setBounds(20,50,150,20);//x,y,width,height
jtn2.setBounds(180,50,150,20);
btnadd.setBounds(180,80,150,20);
btnsub.setBounds(350,80,150,20);
btnadd.addActionListener(this);
btnsub.addActionListener(this);
add(n1);
add(n2);
add(jtn1);
add(jtn2);
add(btnadd);
add(btnsub);
btnsub.setBackground(Color.GREEN);
setSize(600,300);
setLocationRelativeTo(null);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public void actionPerformed(ActionEvent ae){
int a = Integer.parseInt(jtn1.getText());
int b = Integer.parseInt(jtn2.getText());
if(ae.getSource()==btnadd){
ans.setText("Sum"+(a+b));
add(ans);
}else if(ae.getSource()==btnsub){
ans.setText("Diff"+(a-b));
add(ans);
}
}
public static void main(String[] yyy){
mathsss_demo m = new mathsss_demo();
}
}