Categories

Sep 3, 2019 in JAVA

Q: java calculator

1 Answer

Sep 4, 2019
Calculator in Java with Source Code

Calculator in Java with Source Code: We can develop calculator in java with the help of AWT/Swing with event handling. Let's see the code of creating calculator in java.

/*********************************************

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.

***********************************************/
Click here to read more about JAVA
Click here to read more about Insurance

Related questions

Madanswer
Sep 3, 2019 in JAVA
Jun 17, 2019 in JAVA
Jun 17, 2019 in JAVA
...