A Java program for Calculator

Program code:


package UdpServer;

import java.awt.*;
import java.awt.event.*;
 
 
public class calci 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;
///////////////////////////
calci(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 calci("Calculator - JavaTpoint");
}
}
 

 
class MyDigitButton extends Button implements ActionListener
{
calci cl;
 

MyDigitButton(int x,int y, int width,int height,String cap, calci 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
{
calci cl;
 
MyOperatorButton(int x,int y, int width,int height,String cap, calci 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(calci.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(calci.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(calci.getFormattedText(temp));
//cl.number=temp;
}//actionPerformed
}//class
 
/****************************************/
 
class MyMemoryButton extends Button implements ActionListener
{
calci cl;
 

MyMemoryButton(int x,int y, int width,int height,String cap, calci 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(calci.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
{
calci cl;
 
MySpecialButton(int x,int y, int width,int height,String cap, calci 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
}//


Output