TextFieldExample2.java

import javax.swing.*;
import java.awt.event.*;
public class TextFieldExample2 implements ActionListener
{
JTextField tf1,tf2,tf3;
JButton b1,b2;
TextFieldExample2()
{
    JFrame f=new JFrame();
    tf1=new JTextField();
    tf1.setBounds(50,50,150,20);
    tf2=new JTextField();
    tf2.setBounds(50,100,150,20);
    tf3=new JTextField();
    tf3.setBounds(50,150,150,20);
    tf3.setEditable(false);
    b1=new JButton("+");
    b1.setBounds(50,200,50,50);
    b2=new JButton("-");
    b2.setBounds(120,200,50,50);
    b1.addActionListener(this);
    b2.addActionListener(this);
    f.add(tf1);
    f.add(tf2);
    f.add(tf3);
    f.add(b1);
    f.add(b2);
    f.setSize(300,300);
    f.setLayout(null);
    f.setVisible(true);
}
public void actionPerformed(ActionEvent e)
{
    String s1=tf1.getText();
    String s2=tf2.getText();
    int a=Integer.parseInt(s1);
    int b=Integer.parseInt(s2);
    int c=0;
    if(e.getSource()==b1)
    {
        c=a+b;
    }
    else if(e.getSource()==b2)
    {
        c=a-b;
    }
    String result=String.valueOf(c);
    tf3.setText(result);
}
public static void main(String ar[])
{
    new TextFieldExample2();
}
}