package com.wuman;
import java.awt.Color;
import java.awt.BorderLayout;
import java.awt.event.*;
import java.awt.Rectangle;
import java.awt.GridLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.JPanel;
public class Calculator extends JFrame implements ActionListener {//继承
JFrame，他是 Frame 的子类
/*
* 定义一些私有变量，组件（所有的按钮） ,这些按钮和文本框以及符号都
是各个类的对象
*/
private static final long serialVersionUID= 1L;//给个序列号， 保证对象串行
化和存储
/**计算器上的键的名字*/
private final String[] KEYS={
"7","8","9","÷",
"sqrt","4","5","6",
"*","cbrt","1","2","3",
"-","1/x","0",".",
"=","+","%"};
/**计算器上的功能键的名字*/
private final String[] COMMAND={"AC","←","EXIT"};
/**计算器上的函数键的名字*/
private final String[] FUNCTIONWEST={
"sin","cos",
"asin","acos",
"x^2","x^3",
"lg","n!",};
private final String[] FUNCTIONEAST={
"tan","(",
