} public void calculate(double x){ if(lastCommand.equals("+")) result +=x; else if(lastCommand.equals("-")) result -=x; else if(lastCommand.equals("/")) result /=x; else if(lastCommand.equals("=")) result =x; display.setText(""+result); } } public class Calculator{ public static void main(String[] args){ MyFrame jisuan=new MyFrame(); jisuan.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); jisuan.setVisible(true); } }
楼主应该是要控制台 DOS下运行的那个版本吧
import java.util.Scanner;public class Calc { public static void main(String[] args) { Scanner input = new Scanner(System.in); int select = -1; double num1,num2,result; boolean flag = true; do { System.out.println("请选择功能(输入相应的编号):"); System.out.println("1.加法 2.减法 3.乘法 4.除法 5.退出"); select = input.nextInt(); if(select < 1 || select > 5) { System.out.println("请选择合适的功能!"); continue; } else if(select == 5) { flag = false; break; } System.out.println("请输入参加运算的两个数:"); num1 = input.nextDouble(); num2 = input.nextDouble(); switch(select) { case 1: result = num1 + num2; System.out.println(num1 + "+" + num2 + "=" + result); break; case 2: result = num1 - num2; System.out.println(num1 + "-" + num2 + "=" + result); break; case 3: result = num1 * num2; System.out.println(num1 + "*" + num2 + "=" + result); break; case 4: if(num2 == 0) { System.out.println("除数不能为0!"); continue; } result = num1 / num2; System.out.println(num1 + "/" + num2 + "=" + result); break; } } while(flag); } }
import java.applet.*;import java.awt.event.*;import javax.swing.AbstractButton;
import javax.swing.JFrame;import javax.swing.*;
class MyFrame extends JFrame
{
public MyFrame(){
setTitle("计算器");
MyPanel panel= new MyPanel();
add(panel);
pack();
}
}class MyPanel extends JPanel{
private JButton display;
private JPanel panel;
private double result;
private String lastCommand;
private boolean start;
public MyPanel(){
setLayout(new BorderLayout());
result= 0;
lastCommand="=";
start=true;
display=new JButton("0");
display.setEnabled(false);
add(display,BorderLayout.NORTH);
ActionListener insert =new InsertAction();
ActionListener command = new CommandAction();
panel= new JPanel();
panel.setLayout(new GridLayout(4,4));
addButton("7",insert);
addButton("8",insert);
addButton("9",insert);
addButton("/",command);
addButton("4",insert);
addButton("5",insert);
addButton("6",insert);
addButton("*",command);
addButton("1",insert);
addButton("2",insert);
addButton("3",insert);
addButton("0",insert);
addButton(".",insert);
addButton("-",command);
addButton("=",command);
add(panel,BorderLayout.CENTER);
addButton("+",command);
}
private void addButton(String label,ActionListener listener){
JButton button =new JButton(label);
button.addActionListener(listener);
panel.add(button);
}
private class InsertAction implements ActionListener{
public void actionPerformed(ActionEvent e) {
String input=e.getActionCommand();
if(start){
display.setText("");
start = false;
}
display.setText(display.getText()+input);
}
}
private class CommandAction implements ActionListener{
public void actionPerformed(ActionEvent e) {
String command =e.getActionCommand();
if(start){
if(command.equals("-")){
display.setText(command);
start=false;
}
else
lastCommand=command;
}
else{
calculate(Double.parseDouble(display.getText()));
lastCommand=command;
start = true;
}
}
}
public void calculate(double x){
if(lastCommand.equals("+"))
result +=x;
else if(lastCommand.equals("-"))
result -=x;
else if(lastCommand.equals("/"))
result /=x;
else if(lastCommand.equals("="))
result =x;
display.setText(""+result);
}
}
public class Calculator{
public static void main(String[] args){
MyFrame jisuan=new MyFrame();
jisuan.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jisuan.setVisible(true);
}
}
import java.util.Scanner;public class Calc {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int select = -1;
double num1,num2,result;
boolean flag = true;
do {
System.out.println("请选择功能(输入相应的编号):");
System.out.println("1.加法 2.减法 3.乘法 4.除法 5.退出");
select = input.nextInt();
if(select < 1 || select > 5) {
System.out.println("请选择合适的功能!");
continue;
} else if(select == 5) {
flag = false;
break;
}
System.out.println("请输入参加运算的两个数:");
num1 = input.nextDouble();
num2 = input.nextDouble();
switch(select) {
case 1:
result = num1 + num2;
System.out.println(num1 + "+" + num2 + "=" + result);
break;
case 2:
result = num1 - num2;
System.out.println(num1 + "-" + num2 + "=" + result);
break;
case 3:
result = num1 * num2;
System.out.println(num1 + "*" + num2 + "=" + result);
break;
case 4:
if(num2 == 0) {
System.out.println("除数不能为0!");
continue;
}
result = num1 / num2;
System.out.println(num1 + "/" + num2 + "=" + result);
break;
}
} while(flag);
}
}