How To Make a Calculator In Java With Source Code

Hello everyone in this tutorial I will be showing you how to make a calculator in java with source code. It’s a very simple process for making a calculator with nice design by some source code in Java.

Java is a very powerful code language for make any software or apps. The Google Play Store depends on Java programs. So many apps developer around the world work for google play store. They build the programs with java codes.

If you wanna be a good apps developer you first need to have a good knowledge about Java Programming  Language. Whatever, now I will provide you Java Source Codes for making a calculator in Java.
Read Also:
1. How To Make IP Finder In Java With Source Code
2. How To Find Motherboard Model Number In Your PC
3. How to Make Google Adsense HTML Encoder/Parser Tool in Blogger Blog Page

Make a Calculator In Java With Source Code

Java Source Code For Make A Calculator

/********************************************* 
Save this file as MyCalculator.java 
to compile it use 
    javac MyCalculator.java 
to use the calcuator do this 
    java MyCalculator 
**********************************************/  
import java.awt.*;  
import java.awt.event.*;  
/*********************************************/  
  
public class MyCalculator extends Frame  
{  
  
public boolean setClear=true;  
double number, memValue;  
char op;  
  
String digitButtonText[] = {“7”, “8”, “9”, “4”, “5”, “6”, “1”, “2”, “3”, “0”, “+/-“, “.” };  
String operatorButtonText[] = {“/”, “sqrt”, “*”, “%”, “-“, “1/X”, “+”, “=” };  
String memoryButtonText[] = {“MC”, “MR”, “MS”, “M+” };  
String specialButtonText[] = {“Backspc”, “C”, “CE” };  
  
MyDigitButton digitButton[]=new MyDigitButton[digitButtonText.length];  
MyOperatorButton operatorButton[]=new MyOperatorButton[operatorButtonText.length];  
MyMemoryButton memoryButton[]=new MyMemoryButton[memoryButtonText.length];  
MySpecialButton specialButton[]=new MySpecialButton[specialButtonText.length];  
  
Label displayLabel=new Label(“0”,Label.RIGHT);  
Label memLabel=new Label(” “,Label.RIGHT);  
  
final int FRAME_WIDTH=325,FRAME_HEIGHT=325;  
final int HEIGHT=30, WIDTH=30, H_SPACE=10,V_SPACE=10;  
final int TOPX=30, TOPY=50;  
///////////////////////////  
MyCalculator(String frameText)//constructor  
{  
super(frameText);  
  
int tempX=TOPX, y=TOPY;  
displayLabel.setBounds(tempX,y,240,HEIGHT);  
displayLabel.setBackground(Color.BLUE);  
displayLabel.setForeground(Color.WHITE);  
add(displayLabel);  
  
memLabel.setBounds(TOPX,  TOPY+HEIGHT+ V_SPACE,WIDTH, HEIGHT);  
add(memLabel);  
  
// set Co-ordinates for Memory Buttons  
tempX=TOPX;   
y=TOPY+2*(HEIGHT+V_SPACE);  
for(int i=0; i<memoryButton.length; i++)  
{  
memoryButton[i]=new MyMemoryButton(tempX,y,WIDTH,HEIGHT,memoryButtonText[i], this);  
memoryButton[i].setForeground(Color.RED);  
y+=HEIGHT+V_SPACE;  
}  
  
//set Co-ordinates for Special Buttons  
tempX=TOPX+1*(WIDTH+H_SPACE); y=TOPY+1*(HEIGHT+V_SPACE);  
for(int i=0;i<specialButton.length;i++)  
{  
specialButton[i]=new MySpecialButton(tempX,y,WIDTH*2,HEIGHT,specialButtonText[i], this);  
specialButton[i].setForeground(Color.RED);  
tempX=tempX+2*WIDTH+H_SPACE;  
}  
  
//set Co-ordinates for Digit Buttons  
int digitX=TOPX+WIDTH+H_SPACE;  
int digitY=TOPY+2*(HEIGHT+V_SPACE);  
tempX=digitX;  y=digitY;  
for(int i=0;i<digitButton.length;i++)  
{  
digitButton[i]=new MyDigitButton(tempX,y,WIDTH,HEIGHT,digitButtonText[i], this);  
digitButton[i].setForeground(Color.BLUE);  
tempX+=WIDTH+H_SPACE;  
if((i+1)%3==0){tempX=digitX; y+=HEIGHT+V_SPACE;}  
}  
  
//set Co-ordinates for Operator Buttons  
int opsX=digitX+2*(WIDTH+H_SPACE)+H_SPACE;  
int opsY=digitY;  
tempX=opsX;  y=opsY;  
for(int i=0;i<operatorButton.length;i++)  
{  
tempX+=WIDTH+H_SPACE;  
operatorButton[i]=new MyOperatorButton(tempX,y,WIDTH,HEIGHT,operatorButtonText[i], this);  
operatorButton[i].setForeground(Color.RED);  
if((i+1)%2==0){tempX=opsX; y+=HEIGHT+V_SPACE;}  
}  
  
addWindowListener(new WindowAdapter()  
{  
public void windowClosing(WindowEvent ev)  
{System.exit(0);}  
});  
  
setLayout(null);  
setSize(FRAME_WIDTH,FRAME_HEIGHT);  
setVisible(true);  
}  
//////////////////////////////////  
static String getFormattedText(double temp)  
{  
String resText=””+temp;  
if(resText.lastIndexOf(“.0”)>0)  
    resText=resText.substring(0,resText.length()-2);  
return resText;  
}  
////////////////////////////////////////  
public static void main(String []args)  
{  
new MyCalculator(“Calculator – JavaTpoint”);  
}  
}  
  
/*******************************************/  
  
class MyDigitButton extends Button implements ActionListener  
{  
MyCalculator cl;  
  
//////////////////////////////////////////  
MyDigitButton(int x,int y, int width,int height,String cap, MyCalculator clc)  
{  
super(cap);  
setBounds(x,y,width,height);  
this.cl=clc;  
this.cl.add(this);  
addActionListener(this);  
}  
////////////////////////////////////////////////  
static boolean isInString(String s, char ch)  
{  
for(int i=0; i<s.length();i++) if(s.charAt(i)==ch) return true;  
return false;  
}  
/////////////////////////////////////////////////  
public void actionPerformed(ActionEvent ev)  
{  
String tempText=((MyDigitButton)ev.getSource()).getLabel();  
  
if(tempText.equals(“.”))  
{  
 if(cl.setClear)   
    {cl.displayLabel.setText(“0.”);cl.setClear=false;}  
 else if(!isInString(cl.displayLabel.getText(),’.’))  
    cl.displayLabel.setText(cl.displayLabel.getText()+”.”);  
 return;  
}  
  
int index=0;  
try{  
        index=Integer.parseInt(tempText);  
    }catch(NumberFormatException e){return;}  
  
if (index==0 && cl.displayLabel.getText().equals(“0”)) return;  
  
if(cl.setClear)  
            {cl.displayLabel.setText(“”+index);cl.setClear=false;}  
else  
    cl.displayLabel.setText(cl.displayLabel.getText()+index);  
}//actionPerformed  
}//class defination  
  
/********************************************/  
  
class MyOperatorButton extends Button implements ActionListener  
{  
MyCalculator cl;  
  
MyOperatorButton(int x,int y, int width,int height,String cap, MyCalculator clc)  
{  
super(cap);  
setBounds(x,y,width,height);  
this.cl=clc;  
this.cl.add(this);  
addActionListener(this);  
}  
///////////////////////  
public void actionPerformed(ActionEvent ev)  
{  
String opText=((MyOperatorButton)ev.getSource()).getLabel();  
  
cl.setClear=true;  
double temp=Double.parseDouble(cl.displayLabel.getText());  
  
if(opText.equals(“1/x”))  
    {  
    try  
        {double tempd=1/(double)temp;  
        cl.displayLabel.setText(MyCalculator.getFormattedText(tempd));}  
    catch(ArithmeticException excp)  
                        {cl.displayLabel.setText(“Divide by 0.”);}  
    return;  
    }  
if(opText.equals(“sqrt”))  
    {  
    try  
        {double tempd=Math.sqrt(temp);  
        cl.displayLabel.setText(MyCalculator.getFormattedText(tempd));}  
            catch(ArithmeticException excp)  
                    {cl.displayLabel.setText(“Divide by 0.”);}  
    return;  
    }  
if(!opText.equals(“=”))  
    {  
    cl.number=temp;  
    cl.op=opText.charAt(0);  
    return;  
    }  
// process = button pressed  
switch(cl.op)  
{  
case ‘+’:  
    temp+=cl.number;break;  
case ‘-‘:  
    temp=cl.number-temp;break;  
case ‘*’:  
    temp*=cl.number;break;  
case ‘%’:  
    try{temp=cl.number%temp;}  
    catch(ArithmeticException excp)  
        {cl.displayLabel.setText(“Divide by 0.”); return;}  
    break;  
case ‘/’:  
    try{temp=cl.number/temp;}  
        catch(ArithmeticException excp)  
                {cl.displayLabel.setText(“Divide by 0.”); return;}  
    break;  
}//switch  
  
cl.displayLabel.setText(MyCalculator.getFormattedText(temp));  
//cl.number=temp;  
}//actionPerformed  
}//class  
  
/****************************************/  
  
class MyMemoryButton extends Button implements ActionListener  
{  
MyCalculator cl;  
  
/////////////////////////////////  
MyMemoryButton(int x,int y, int width,int height,String cap, MyCalculator clc)  
{  
super(cap);  
setBounds(x,y,width,height);  
this.cl=clc;  
this.cl.add(this);  
addActionListener(this);  
}  
////////////////////////////////////////////////  
public void actionPerformed(ActionEvent ev)  
{  
char memop=((MyMemoryButton)ev.getSource()).getLabel().charAt(1);  
  
cl.setClear=true;  
double temp=Double.parseDouble(cl.displayLabel.getText());  
  
switch(memop)  
{  
case ‘C’:   
    cl.memLabel.setText(” “);cl.memValue=0.0;break;  
case ‘R’:   
    cl.displayLabel.setText(MyCalculator.getFormattedText(cl.memValue));break;  
case ‘S’:  
    cl.memValue=0.0;  
case ‘+’:   
    cl.memValue+=Double.parseDouble(cl.displayLabel.getText());  
    if(cl.displayLabel.getText().equals(“0”) || cl.displayLabel.getText().equals(“0.0”)  )  
        cl.memLabel.setText(” “);  
    else   
        cl.memLabel.setText(“M”);     
    break;  
}//switch  
}//actionPerformed  
}//class  
  
/*****************************************/  
  
class MySpecialButton extends Button implements ActionListener  
{  
MyCalculator cl;  
  
MySpecialButton(int x,int y, int width,int height,String cap, MyCalculator clc)  
{  
super(cap);  
setBounds(x,y,width,height);  
this.cl=clc;  
this.cl.add(this);  
addActionListener(this);  
}  
//////////////////////  
static String backSpace(String s)  
{  
String Res=””;  
for(int i=0; i<s.length()-1; i++) Res+=s.charAt(i);  
return Res;  
}  
  
//////////////////////////////////////////////////////////  
public void actionPerformed(ActionEvent ev)  
{  
String opText=((MySpecialButton)ev.getSource()).getLabel();  
//check for backspace button  
if(opText.equals(“Backspc”))  
{  
String tempText=backSpace(cl.displayLabel.getText());  
if(tempText.equals(“”))   
    cl.displayLabel.setText(“0”);  
else   
    cl.displayLabel.setText(tempText);  
return;  
}  
//check for “C” button i.e. Reset  
if(opText.equals(“C”))   
{  
cl.number=0.0; cl.op=’ ‘; cl.memValue=0.0;  
cl.memLabel.setText(” “);  
}  
  
//it must be CE button pressed  
cl.displayLabel.setText(“0”);cl.setClear=true;  
}//actionPerformed  
}//class  
  
/********************************************* 
Features not implemented and few bugs 
i)  No coding done for “+/-” button. 
ii) Menubar is not included. 
iii)Not for Scientific calculation 
iv)Some of the computation may lead to unexpected result 
   due to the representation of Floating point numbers in computer 
   is an approximation to the given value that can be stored 
   physically in memory. 
***********************************************/  

♦ If you wanna to make a calculator in Java using the Swing. Then use below code to make a calculator like a screenshot. Let’s see;

Make a Calculator in Java Using Swing

Programs to Make a Calculator in Java Using Swing 

import javax.swing.*;

import java.awt.event.*;
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;
    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”);
        
        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.setLayout(null);
        f.setVisible(true);
        f.setSize(350,500);
        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…s)
    {
        new Calc();
    }
}

Here is two king of source code in Java for making Calculator. Hopefully, your are done with success. If have any trouble in these codes for making a calculator. Inform me via the comment section. I will try to solve it with my best.

1 thought on “How To Make a Calculator In Java With Source Code”

Leave a Comment