How to make calculator program in java using swing.

This Post is about how to create calculator program in Java using swing. Nowadays Java become most popular Programming Language to develop advance web and desktop application.

• Below I will show you how to make calculator program in core java using swing api. Swing basically used for provide enhance view if GUI component like Button,Label,List,Frame Etc.

• Swing is alternative of AWT Component. This Calculator Perform simple calculator operation like Arithmetic,addition, subtraction, multiplication and division of two numbers.

Calculator program in Java

import javax.swing.*;
import java.awt.event.*;
import java.awt.*;

public class Calc implements ActionListener {
    
    JFrame f;
    JTextField t;
    JButton b1,b2,b3,b4,b5,b6,b7,b8,b9,b0,bdiv,bmul,bsub,badd,bdec,beq,bdel,bclr;
    JLabel l1;
    static double a=0,b=0,result=0;
    static int operator=0;
    Calc()
    {
        f=new JFrame("Calculator");
        t=new JTextField();
        b1=new JButton("1");
        b2=new JButton("2");
        b3=new JButton("3");
        b4=new JButton("4");
        b5=new JButton("5");
        b6=new JButton("6");
        b7=new JButton("7");
        b8=new JButton("8");
        b9=new JButton("9");
        b0=new JButton("0");
        bdiv=new JButton("/");
        bmul=new JButton("*");
        bsub=new JButton("-");
        badd=new JButton("+");
        bdec=new JButton(".");
        beq=new JButton("=");
        bdel=new JButton("Delete");
        bclr=new JButton("Clear");
        l1 = new JLabel("www.TechsoftTutorials.com", JLabel.CENTER);
        l1.setSize(500,50);
        l1.setBackground(Color.GRAY);
        l1.setForeground(Color.RED);
        t.setBounds(30,40,280,30);
        b7.setBounds(40,100,50,40);
        b8.setBounds(110,100,50,40);
        b9.setBounds(180,100,50,40);
        bdiv.setBounds(250,100,50,40);
        
        b4.setBounds(40,170,50,40);
        b5.setBounds(110,170,50,40);
        b6.setBounds(180,170,50,40);
        bmul.setBounds(250,170,50,40);
        
        b1.setBounds(40,240,50,40);
        b2.setBounds(110,240,50,40);
        b3.setBounds(180,240,50,40);
        bsub.setBounds(250,240,50,40);
        
        bdec.setBounds(40,310,50,40);
        b0.setBounds(110,310,50,40);
        beq.setBounds(180,310,50,40);
        badd.setBounds(250,310,50,40);
        
        bdel.setBounds(60,380,100,40);
        bclr.setBounds(180,380,100,40);
        
        f.add(t);
        f.add(b7);
        f.add(b8);
        f.add(b9);
        f.add(bdiv);
        f.add(b4);
        f.add(b5);
        f.add(b6);
        f.add(bmul);
        f.add(b1);
        f.add(b2);
        f.add(b3);
        f.add(bsub);
        f.add(bdec);
        f.add(b0);
        f.add(beq);
        f.add(badd);
        f.add(bdel);
        f.add(bclr);
        f.add(l1);
        
        f.setLayout(null);
        f.setVisible(true);
        f.setSize(500,500);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setResizable(false);
        
        b1.addActionListener(this);
        b2.addActionListener(this);
        b3.addActionListener(this);
        b4.addActionListener(this);
        b5.addActionListener(this);
        b6.addActionListener(this);
        b7.addActionListener(this);
        b8.addActionListener(this);
        b9.addActionListener(this);
        b0.addActionListener(this);
        badd.addActionListener(this);
        bdiv.addActionListener(this);
        bmul.addActionListener(this);
        bsub.addActionListener(this);
        bdec.addActionListener(this);
        beq.addActionListener(this);
        bdel.addActionListener(this);
        bclr.addActionListener(this);
    }
 
    public void actionPerformed(ActionEvent e)
    {
        if(e.getSource()==b1)
            t.setText(t.getText().concat("1"));
        
        if(e.getSource()==b2)
            t.setText(t.getText().concat("2"));
        
        if(e.getSource()==b3)
            t.setText(t.getText().concat("3"));
        
        if(e.getSource()==b4)
            t.setText(t.getText().concat("4"));
        
        if(e.getSource()==b5)
            t.setText(t.getText().concat("5"));
        
        if(e.getSource()==b6)
            t.setText(t.getText().concat("6"));
        
        if(e.getSource()==b7)
            t.setText(t.getText().concat("7"));
        
        if(e.getSource()==b8)
            t.setText(t.getText().concat("8"));
        
        if(e.getSource()==b9)
            t.setText(t.getText().concat("9"));
        
        if(e.getSource()==b0)
            t.setText(t.getText().concat("0"));
        
        if(e.getSource()==bdec)
            t.setText(t.getText().concat("."));
        
        if(e.getSource()==badd)
        {
            a=Double.parseDouble(t.getText());
            operator=1;
            t.setText("");
        } 
        
        if(e.getSource()==bsub)
        {
            a=Double.parseDouble(t.getText());
            operator=2;
            t.setText("");
        }
        
        if(e.getSource()==bmul)
        {
            a=Double.parseDouble(t.getText());
            operator=3;
            t.setText("");
        }
        
        if(e.getSource()==bdiv)
        {
            a=Double.parseDouble(t.getText());
            operator=4;
            t.setText("");
        }
        
        if(e.getSource()==beq)
        {
            b=Double.parseDouble(t.getText());
        
            switch(operator)
            {
                case 1: result=a+b;
                    break;
        
                case 2: result=a-b;
                    break;
        
                case 3: result=a*b;
                    break;
        
                case 4: result=a/b;
                    break;
        
                default: result=0;
            }
        
            t.setText(""+result);
        }
        
        if(e.getSource()==bclr)
            t.setText("");
        
        if(e.getSource()==bdel)
        {
            String s=t.getText();
            t.setText("");
            for(int i=0;i<s.length()-1;i++)
            t.setText(t.getText()+s.charAt(i));
        }        
    }
    public static void main(String[] args) {
       new Calc();
    }
    
}

OutPut:-