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import javax.swing.JFrame; //Swing Components Class included
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.event.ActionListener; //EventHandler interface & class
import java.awt.event.ActionEvent;
//Step:1-Implementing the ActionListener interface in the class
class SwingAddSub implements ActionListener{
JLabel l1,l2,l3,l4; //JComponents declared
JTextField t1,t2;
JButton b1,b2;
SwingAddSub(){
JFrame jf=new JFrame("Calculator");
jf.setVisible(true); //making the frame visible
jf.setSize(300,300); //300 width and 300 height
jf.setLayout(null); //using no layout managers
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//JComponents created
l1=new JLabel("Addition/Subtraction on 2 Numbers");
l2=new JLabel("First number");
l3=new JLabel("Second Number");
l4=new JLabel();
t1=new JTextField();
t2=new JTextField();
b1=new JButton("+");
b2=new JButton("Sub");
//adding components created in JFrame
jf.add(l1);
jf.add(l2);
jf.add(l3);
jf.add(l4);
jf.add(t1);
jf.add(t2);
jf.add(b1);
jf.add(b2);
//x axis, y axis, width, height
l1.setBounds(50,50,200,20);
l2.setBounds(50,80,100,20);
t1.setBounds(150,80,100,20);
l3.setBounds(50,130,100,20);
t2.setBounds(150,130,100,20);
b1.setBounds(80,180,100,20);
b2.setBounds(80,210,100,20);
l4.setBounds(50,240,100,20);
//Step:2-Registering the component with the Listener
b1.addActionListener(this);//(this->instanceOfListenerclass)
b2.addActionListener(this);
}
//Step:3-Overridding the actionPerformed() method
public void actionPerformed(ActionEvent e){
String s1 = e.getActionCommand();
System.out.println(s1);
if (s1.equals("+")) {
String x=t1.getText();
String y=t2.getText();
int a = Integer.parseInt(x);
int b = Integer.parseInt(y);
int sum=a+b;
l4.setText("Result is : "+sum);
}
if (s1.equals("Sub")){
String x=t1.getText();
String y=t2.getText();
int a = Integer.parseInt(x);
int b = Integer.parseInt(y);
int sub=a-b;
l4.setText("Result is : "+sub);
}
}
}
public class SwingAddSubDemo{
public static void main(String[] args){
new SwingAddSub();
}
}