Scientific calculator in java

Scientific Calculator source code developed in java swing

Description : A simple Java Swing Calculator, Example for setBounds in java, Example for actionListener interface. Here i tried to Implement a simple Java Calculator. copy and paste the code to a notepad. compile the program with javac and run using command prompt java calculator

Author +belazy

/* this is a program to make a

calculator

using java program */

/* For SNR Sons Lab exam ...
 * @author belazy
 */




import java.awt.*;
import java.awt.event.*;

public class

Calculator

extends Frame implements ActionListener

{
Button b1,b2,b3,b4,b5,b6,b7,b8,b9,b0,ex,p1,eq,min,div,mul,cl,back;
TextField t;
int n,i;
int n1,n2;
int ans;

Calculator()
{
this.setLayout(null);
b0=new Button(" 0 ");
b1=new Button(" 1 ");
b2=new Button(" 2 ");
b3=new Button(" 3 ");
b4=new Button(" 4 ");
b5=new Button(" 5 ");
b6=new Button(" 6 ");
b7=new Button(" 7 ");
b8=new Button(" 8 ");
b9=new Button(" 9 ");
ex=new Button("exit");
p1=new Button("+");
min=new Button("-");
mul=new Button("X");
div=new Button("/");

eq=new Button("=");
cl=new Button("AC");
back=new Button("clear");

t=new TextField(40);

b0.setBounds(130,190,30,30);
b1.setBounds(100,100,30,30);
b2.setBounds(130,100,30,30);
b3.setBounds(160,100,30,30);
b4.setBounds(100,130,30,30);
b5.setBounds(130,130,30,30);
b6.setBounds(160,130,30,30);
b7.setBounds(100,160,30,30);
b8.setBounds(130,160,30,30);
b9.setBounds(160,160,30,30);
ex.setBounds(100,190,30,30);
p1.setBounds(190,100,30,30);
min.setBounds(190,130,30,30);
mul.setBounds(190,160,30,30);
div.setBounds(190,190,30,30);
eq.setBounds(160,190,30,30);
cl.setBounds(220,100,30,30);
back.setBounds(220,130,30,30);

t.setBounds(100,60,150,30);



this.add(b0);
this.add(b1);
this.add(b2);
this.add(b3);
this.add(b4);
this.add(b5);
this.add(b6);
this.add(b7);
this.add(b8);
this.add(b9);

this.add(ex);
this.add(p1);
this.add(mul);
this.add(min);
this.add(div);
this.add(eq);
this.add(cl);
this.add(back);

this.add(t);

b0.addActionListener(this);
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);

ex.addActionListener(this);
p1.addActionListener(this);
mul.addActionListener(this);
div.addActionListener(this);
min.addActionListener(this);
eq.addActionListener(this);
cl.addActionListener(this);
back.addActionListener(this);
}


public void actionPerformed(ActionEvent ae)

{

if(ae.getSource()==ex)
{
System.exit(0);
}

if(ae.getSource()==p1) // while pressing plus
{

n1=Integer.parseInt(t.getText());
i=1; // this expression is for equals
t.setText("0");

}

if(ae.getSource()==min) // while pressing minus
{

n1=Integer.parseInt(t.getText());
i=2;
t.setText("0");

}

if(ae.getSource()==mul) // while pressing multiplication
{

n1=Integer.parseInt(t.getText());
i=3;
t.setText("0");

}

if(ae.getSource()==div) // while pressing division
{

n1=Integer.parseInt(t.getText());
i=4;
t.setText("0");

}
if(ae.getSource()==cl) // while pressing all clear
{

//n1=Integer.parseInt(t.getText());
//i=4;
t.setText("0");

}

if (ae.getSource()==back) // for back space
{
//if (!(t.getText().equals("0") && t.getText().length() > 1)

t.setText(t.getText().substring(0,t.getText().length()-1));

}




if(ae.getSource()==b0)
{
if(t.getText().equals("0"))
t.setText("0");
else
t.setText(t.getText() +"0");
}

if(ae.getSource()==b1)
{
if(t.getText().equals("0"))
t.setText("1");
else
t.setText(t.getText() +"1");
}

if(ae.getSource()==b2)
{
if(t.getText().equals("0"))
t.setText("2");
else
t.setText(t.getText() +"2");
}


if(ae.getSource()==b3)
{
if(t.getText().equals("0"))
t.setText("3");
else
t.setText(t.getText() +"3");
}

if(ae.getSource()==b4)
{
if(t.getText().equals("0"))
t.setText("4");
else
t.setText(t.getText() +"4");
}

if(ae.getSource()==b5)
{
if(t.getText().equals("0"))
t.setText("5");
else
t.setText(t.getText() +"5");
}

if(ae.getSource()==b6)
{
if(t.getText().equals("0"))
t.setText("6");
else
t.setText(t.getText() +"6");
}

if(ae.getSource()==b7)
{
if(t.getText().equals("0"))
t.setText("7");
else
t.setText(t.getText() +"7");
}

if(ae.getSource()==b8)
{
if(t.getText().equals("0"))
t.setText("8");
else
t.setText(t.getText() +"8");
}

if(ae.getSource()==b9)
{
if(t.getText().equals("0"))
t.setText("9");
else
t.setText(t.getText() +"9");
}
System.out.println(t.getText());

if(ae.getSource()==eq) //while pressing equals
{
n2=Integer.parseInt(t.getText());




switch(i)
{
case 1:
{

ans=n1+n2;
t.setText(Integer.toString(ans));
n1=0;
n2=0;
}
break;

case 2:
{

ans=n1-n2;
t.setText(Integer.toString(ans));
n1=0;
n2=0;

}
break;

case 3:
{

ans=n1*n2;
t.setText(Integer.toString(ans));
n1=0;
n2=0;

}
break;

case 4:
{

ans=n1/n2;
t.setText(Integer.toString(ans));
n1=0;
n2=0;

}
break;

}

}



}



public static void main(String free[])
{

Calculator c= new Calculator();
c.setTitle("

simple java calculator source code

");
c.setSize(600,600);
c.setVisible(true);

}

}


Hi Friends,

           This is my first program in java. so please try it out and find the issues. Thanks to ravi, vishnu , madhu, bithesh and nithin for support

/* contact me at belazy1987atgmail.com */

Most selling calculator in amazon ( Price around 1000) The best one, Buy this , worth buying.
fx-991 Ex ( Casio - the best calculator makers )

Hurry !! Before stock out

Another Program send by my friend,

simple java calculator source code

import javax.swing.*;
import javax.swing.JOptionPane;
import java.awt.*;
import java.awt.event.*;
//<applet code=Calculator height=300 width=200></applet>
public class Calculator extends JApplet {
public void init() {
CalculatorPanel calc=new CalculatorPanel();
getContentPane().add(calc);
}
}

class CalculatorPanel extends JPanel implements ActionListener {
JButton
n1,n2,n3,n4,n5,n6,n7,n8,n9,n0,plus,minus,mul,div,dot,equal;
static JTextField result=new JTextField("0",45);
static String lastCommand=null;
JOptionPane p=new JOptionPane();
double preRes=0,secVal=0,res;

private static void assign(String no)
{
if((result.getText()).equals("0"))
result.setText(no);
else if(lastCommand=="=")
{
result.setText(no);
lastCommand=null;
}
else
result.setText(result.getText()+no);
}

public CalculatorPanel() {
setLayout(new BorderLayout());
result.setEditable(false);
result.setSize(300,200);
add(result,BorderLayout.NORTH);
JPanel panel=new JPanel();
panel.setLayout(new GridLayout(4,4));

n7=new JButton("7");
panel.add(n7);
n7.addActionListener(this);
n8=new JButton("8");
panel.add(n8);
n8.addActionListener(this);
n9=new JButton("9");
panel.add(n9);
n9.addActionListener(this);
div=new JButton("/");
panel.add(div);
div.addActionListener(this);

n4=new JButton("4");
panel.add(n4);
n4.addActionListener(this);
n5=new JButton("5");
panel.add(n5);
n5.addActionListener(this);
n6=new JButton("6");
panel.add(n6);
n6.addActionListener(this);
mul=new JButton("*");
panel.add(mul);
mul.addActionListener(this);

n1=new JButton("1");
panel.add(n1);
n1.addActionListener(this);
n2=new JButton("2");
panel.add(n2);
n2.addActionListener(this);
n3=new JButton("3");
panel.add(n3);
n3.addActionListener(this);
minus=new JButton("-");
panel.add(minus);
minus.addActionListener(this);

dot=new JButton(".");
panel.add(dot);
dot.addActionListener(this);
n0=new JButton("0");
panel.add(n0);
n0.addActionListener(this);
equal=new JButton("=");
panel.add(equal);
equal.addActionListener(this);
plus=new JButton("+");
panel.add(plus);
plus.addActionListener(this);
add(panel,BorderLayout.CENTER);
}
public void actionPerformed(ActionEvent ae)
{
if(ae.getSource()==n1) assign("1");
else if(ae.getSource()==n2) assign("2");
else if(ae.getSource()==n3) assign("3");
else if(ae.getSource()==n4) assign("4");
else if(ae.getSource()==n5) assign("5");
else if(ae.getSource()==n6) assign("6");
else if(ae.getSource()==n7) assign("7");
else if(ae.getSource()==n8) assign("8");
else if(ae.getSource()==n9) assign("9");
else if(ae.getSource()==n0) assign("0");
else if(ae.getSource()==dot)
{
if(((result.getText()).indexOf("."))==-1)
result.setText(result.getText()+".");
}
else if(ae.getSource()==minus)
{
preRes=Double.parseDouble(result.getText());
lastCommand="-";
result.setText("0");
}
else if(ae.getSource()==div)
{
preRes=Double.parseDouble(result.getText());
lastCommand="/";
result.setText("0");
}
else if(ae.getSource()==equal)
{
secVal=Double.parseDouble(result.getText());
if(lastCommand.equals("/"))
res=preRes/secVal;
else if(lastCommand.equals("*"))
res=preRes*secVal;
else if(lastCommand.equals("-"))
res=preRes-secVal;
else if(lastCommand.equals("+"))
res=preRes+secVal;
result.setText(" "+res);
lastCommand="=";
}
else if(ae.getSource()==mul)
{
preRes=Double.parseDouble(result.getText());
lastCommand="*";
result.setText("0");
}
else if(ae.getSource()==plus)
{
preRes=Double.parseDouble(result.getText());
lastCommand="+";
result.setText("0");
}

}
}


The above is an example code for java swing scientific calculator, copy and paste it as calculator.java, compile the code and run it.

Please provide your feedback.

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