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import
java.awt.*;
import
javax.swing.*;
import
java.awt.event.*;
public
class
MyCalculator extends
JFrame{
private
static
final
long
serialVersionUID = 1L;
private
String showStr="",remainStr="",method="";
private
boolean
isCalculated=false;
private
void
setShowStr(String showStr){
this.showStr=showStr;
}
private
String[] str={"C",
"CE",
"+/-",
"7",
"8",
"9",
"4",
"5",
"6",
"1",
"2",
"3","0",
".",
"=",
"+",
"-",
"*",
"/"};
JButton[]
jbt=new
JButton[str.length];
JTextField
jtf=new
JTextField();
public
MyCalculator(){
for
(int
i=0;i<str.length;i++){
jbt[i]=new
JButton(str[i]);
}
JPanel
p1=new
JPanel();
p1.setLayout(new
GridLayout(5,3));
for
(int
i=0;i<str.length-4;i++){
p1.add(jbt[i]);
}
JPanel
p2=new
JPanel();
p2.setLayout(new
GridLayout(4,1));
for
(int
i=str.length-4;i<str.length;i++){
p2.add(jbt[i]);
}
add(jtf,BorderLayout.NORTH);
add(p1,BorderLayout.CENTER);
add(p2,BorderLayout.EAST);
ButtonListener
listener=new
ButtonListener();
for
(int
i=0;i<str.length;i++){
jbt[i].addActionListener(listener);
}
}
class
ButtonListener implements
ActionListener {
public
void
actionPerformed(ActionEvent e){
String
s=e.getActionCommand();
if
(s=="C"&&showStr.length()>0){
showStr=showStr.substring(0,showStr.length()-1);
jtf.setText(showStr);
}//clear
else
if
(s=="CE"){
showStr="";
remainStr="";
isCalculated=false;
jtf.setText(showStr);
}
//clear
all
else
if
(s=="+"||s=="-"||s=="*"||s=="/"){
remainStr=showStr;
showStr="";
method=s;
jtf.setText(showStr);
}
else
if
(s=="+/-"&&showStr==""){
showStr+="-";
jtf.setText(showStr);
}
else
if
(s=="="){
jtf.setText(calculation(remainStr,showStr,method));
}
else
{
if(isCalculated){
showStr="";
jtf.setText(showStr);
isCalculated=false;
}
showStr+=s;
jtf.setText(showStr);
}//number
}
}
private
String calculation(String s1,String s2,String s3){
Double
num1=Double.parseDouble(s1);
Double
num2=Double.parseDouble(s2);
isCalculated=true;
if
(s3=="+"){
setShowStr(num1+num2+"");
return
num1+num2+"";
}
else
if
(s3=="-"){
setShowStr(num1-num2+"");
return
num1-num2+"";
}
else
if
(s3=="*"){
setShowStr(num1*num2+"");
return
num1*num2+"";
}
else
if
(s3=="/"){
setShowStr(num1/num2+"");
return
num1/num2+"";
}
return
"error";
}
public
static
void
main(String[] args){
JFrame
frame=new
MyCalculator();
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
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