import java.applet.*;
import java.awt.event.*;
import java.awt.*;
//<applet code="Slip6" height=300 width=200></applet>
public class Slip6 extends Applet implements ActionListener
{
TextField t;
Button b[];
Panel p;
String c, arr[]={"1","2","3","+","4","5","6","-","7","8","9","*","0",".","=","/"};
double n1,n2,ans;
public void init()
{
t= new TextField(20);
b=new Button[16];
p= new Panel();
for(int i=0;i<16;i++)
b[i]=new Button(arr[i]);
p.setLayout(new GridLayout(4, 4, 10, 10));
p.setSize(700,1500);

}
public void start()
{
add(t);
for(int i=0;i<16;i++)
{
p.add(b[i]);
b[i].addActionListener(this);
}
add(p);
}
public void actionPerformed(ActionEvent ae)
{
switch (ae.getActionCommand())
{
case "1": insert("1"); break;
case "2": insert("2"); break;
case "3": insert("3"); break;
case "4": insert("4"); break;
case "5": insert("5"); break;
case "6": insert("6"); break;
case "7": insert("7"); break;
case "8": insert("8"); break;
case "9": insert("9"); break;
case "0": insert("0"); break;
case ".": insert("."); break;
case "+": addition(); break;
case "-": substract(); break;
case "*": multiply(); break;
case "/": divide(); break;
case "=": cal(); break;
}
}
void insert(String n)
{
if (t.getText().equals(""))
t.setText(n);
else
t.setText(t.getText()+n);
}
void addition()
{
n1=Double.parseDouble(t.getText());
t.setText(t.getText()+"+");
c="+";
}
void substract()
{
n1=Double.parseDouble(t.getText());
t.setText(t.getText()+"-");
c="-";
}
void multiply()
{
n1=Double.parseDouble(t.getText());
t.setText(t.getText()+"*");
c="*";
}
void divide()
{
n1=Double.parseDouble(t.getText());
t.setText(t.getText()+"/");
c="/";
}
void cal()
{
n2=Double.parseDouble(t.getText().substring(t.getText().indexOf(c)+1,t.getText().length()));
if(c.equals("+"))
{
t.setText(Double.toString(n1+n2));
n1=n1+n2;
}
if(c.equals("-"))
{
t.setText(Double.toString(n1-n2));
n1=n1-n2;
}
if(c.equals("*"))
{
t.setText(Double.toString(n1*n2));
n1=n1*n2;
}
if(c.equals("/"))
{
t.setText(Double.toString(n1/n2));
n1=n1/n2;
}
}
}