How do I add multiple integers into the JTextField, like if I already pushed one button and I push another, how do I make it so that the second number adds on to the first.
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
public class Display {
public static void main(String args[]){
int num1;
int num2;
int sum;
final int var;
JFrame frame = new JFrame("Calculator");
frame.setSize(300, 400);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
final JTextField jtf = new JTextField();
jtf.setSize(100, 40);
frame.add(jtf);
jtf.setLocation(100, 1);
JButton one = new JButton(" 1 ");
one.setSize(50, 20);
frame.getContentPane().add(one);
one.setLocation(30, 50);
one.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
jtf.setText("1");
}
}
JButton two = new JButton(" 2 ");
two.setSize(50, 20);
frame.getContentPane().add(two);
two.setLocation(90, 50);
two.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
jtf.setText("2");
}
}
JButton three = new JButton(" 3 ");
three.setSize(50, 20);
frame.getContentPane().add(three);
three.setLocation(150, 50);
three.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
jtf.setText("3");
}
}
JButton add = new JButton(" + ");
add.setSize(50, 20);
frame.getContentPane().add(add);
add.setLocation(210, 50);
add.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
}
}
JButton four = new JButton(" 4 ");
four.setSize(50, 20);
frame.getContentPane().add(four);
four.setLocation(30, 80);
four.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
jtf.setText("4");
}
}
JButton five = new JButton(" 5 ");
five.setSize(50, 20);
frame.getContentPane().add(five);
five.setLocation(90, 80);
five.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
jtf.setText("5");
}
}
JButton six = new JButton(" 6 ");
six.setSize(50, 20);
frame.getContentPane().add(six);
six.setLocation(150, 80);
six.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
jtf.setText("6");
}
}
JButton sub = new JButton(" - ");
sub.setSize(50, 20);
frame.getContentPane().add(sub);
sub.setLocation(210, 80);
sub.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
}
}
JButton seven = new JButton(" 7 ");
seven.setSize(50, 20);
frame.getContentPane().add(seven);
seven.setLocation(30, 110);
seven.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
jtf.setText("7");
}
}
JButton eight = new JButton(" 8 ");
eight.setSize(50, 20);
frame.getContentPane().add(eight);
eight.setLocation(90, 110);
eight.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
jtf.setText("8");
}
}
JButton nine = new JButton(" 9 ");
nine.setSize(50, 20);
frame.getContentPane().add(nine);
nine.setLocation(150, 110);
nine.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
jtf.setText("9");
}
}
JButton mult = new JButton(" * ");
mult.setSize(50, 20);
frame.getContentPane().add(mult);
mult.setLocation(210, 110);
mult.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
}
}
JButton zero = new JButton(" 0 ");
zero.setSize(50, 20);
frame.getContentPane().add(zero);
zero.setLocation(90, 140);
zero.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
jtf.setText("0");
}
}
JButton div = new JButton(" / ");
div.setSize(50, 20);
frame.getContentPane().add(div);
div.setLocation(210, 140);
div.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
}
}
}
}