用JAVA编一个计算器的程序,要里边的注释

Posted 2023-04-21

计算器
 项目概述
计算器
项目名称 计算器
代码量 600 行 项目简介 通过Java控制台程序完成Windows中附件中运算器的功能。
项目目的 通过一个Java控制台程序，流程控制语句的熟练运用程度，对于Java异常处理的掌握和运用程度，以及编码规范度。
通过对项目进行重构，深入领悟OOP技术。
涉及主要技术 Java基本语法
Java输入输出
Java异常控制
Java输入输出
Java容器类
数据库 无
编程环境 JDK 1.5
JCreator / NetBeans
项目特点 控制台界面，单机版简单程序。
技术重点 Java流程控制语句的熟练运用
Java异常处理
从面向过程思想到面向对象思想的转变
技术难点 Java I/O使用（从控制台接收和输出信息）
Java 容器类基本使用
OOP的具体实现

图形界面：

参考技术A package counter;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Counter implements ActionListener
JFrame counter = null;
Container cou = null;
JTextField txt = null;
JPanel pan = null;
JButton [] btn = null;
JLabel lblbrand = null,lbltype = null;
String sign = "",sign1 = "0",sign2 = "",sign3 = "";
char operator = ' ', operator1 = '+';
int i = 0;
double resault = 0;
int b = 0;

public Counter()
counter = new JFrame("计算器");
cou = counter.getContentPane();
cou.setLayout(null);
lblbrand = new JLabel("大象牌");
lblbrand.setForeground(Color.BLUE);
lblbrand.setBounds(15,8,70,20);
cou.add(lblbrand);
lbltype = new JLabel("x-14250");
lbltype.setForeground(Color.GREEN);
lbltype.setBounds(265,8,70,20);
cou.add(lbltype);
txt = new JTextField("0.");
txt.setCaretPosition(2);
txt.setHorizontalAlignment(JTextField.TRAILING);
cou.add(txt);
txt.setBounds(15,28,300,30);
pan = new JPanel(new GridLayout(5,4,10,10));
pan.setBounds(15,68,300,160);
btn = new JButton[20];
String [] btnname = "Off","Back","C","Exit","7","8","9","+","4","5",
"6","-","1","2","3","*","0",".","=","/";
for(int i = 0; i < 20; i++)

btn[i] = new JButton(btnname[i]);
pan.add(btn[i]);
btn[i].addActionListener(this);

btn[7].setFont(new java.awt.Font("宋体", Font.PLAIN, 16));
btn[11].setFont(new java.awt.Font("宋体", Font.PLAIN, 16));
btn[15].setFont(new java.awt.Font("宋体", Font.PLAIN, 16));
btn[17].setFont(new java.awt.Font("宋体", Font.PLAIN, 16));
btn[18].setFont(new java.awt.Font("宋体", Font.PLAIN, 16));
btn[19].setFont(new java.awt.Font("宋体", Font.PLAIN, 16));
cou.add(pan);
counter.setSize(335,280);
counter.setVisible(true);


public void actionPerformed(ActionEvent e)
operator = e.getActionCommand().charAt(0);
annal();
if(!sign.equals(""))
opinion(sign);
else
showresault(sign1);
if(i % 2 != 0)
txt.setText("");


private void annal()
int l = 0;
switch (operator)
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
if (!sign.equals("0"))
sign = sign + Character.toString(operator);
else
sign = sign.concat(Character.toString(operator)).substring(1);
break;
case '0':
if (!sign.equals("") && !sign.equals("0"))
sign = sign + Character.toString(operator);
else
sign = "0";
break;
case 'B':
if (sign.length() > 1 && sign.charAt(txt.getText().length() - 1) != '.')
sign = (sign.substring(0,sign.length() - 1));
else if (sign.length() > 2)
sign = (sign.substring(0,sign.length() - 2));
else
sign = "0";

break;
case 'C':
sign = "";
sign2 = "";
sign1 = "0";
operator = ' ';
break;
case 'E':
System.exit(0);
break;
case 'O':
sign = "";
sign2 = "";
sign1 = "0";
operator = ' ';
i++;
break;
case '+':
case '-':
case '*':
case '/':
count();
break;
case '=':
count();
operator1 = ' ';
sign3 = "-1";
break;
case '.':
if (sign.equals(""))
sign = "0".concat(Character.toString(operator));
else
for (int i = 0; i < sign.length(); i++)
if (sign.charAt(i) == '.')
l++;


if (l == 0)
sign = sign + Character.toString(operator);


break;



private void count()
double number1 = 0,number2 = 0;
if (!sign.equals(""))
sign2 = sign;
else
sign2 = "0";
sign = "";
if (!sign3.equals("-1"))
sign3 = sign1;
else
sign3 = "0";
number1 = Double.valueOf(sign3).doubleValue();
number2 = Double.valueOf(sign2).doubleValue();
switch(operator1)
case '+':
resault = number1 + number2;
break;
case '-':
resault = number1 - number2;
break;
case '*':
resault = number1 * number2;
break;
case '/':
resault = number1 / number2;
break;
case ' ':
resault = Double.valueOf(sign2).doubleValue();

operator1 = operator;
sign1 = Double.toString(resault);


private void showresault(String sign)
int j = sign.length() - 1;
String subsign = "";
for (int i = 0; i <= j; i++)
if (sign.charAt(i) == '.')

j = i;
break;


if (j != sign.length() - 1)
subsign = sign.substring(j+1);
if (Double.valueOf(subsign).doubleValue() > 0)
txt.setText(sign);
else
txt.setText(sign.substring(0, j));

else
txt.setText(sign);


private void opinion(String sign)
txt.setText(sign);


public static void main(String[] args)
Counter counter = new Counter();


这个是以前自己做的一个计算器,可能不是很完善,注释没写,但代码相对简单,应该可以看明白本回答被提问者采纳

摩斯码编解码器

1、背景

　　今天是1024，程序员节那就干点儿程序员的事情。刚好，记得上高中时候，看过一部电影，无间道，里边黄秋生和梁朝伟用摩斯码通信，瞬间觉得好神秘，好帅气。最近闲来无事，出于对当初兴趣的尊敬，就顺手实现了一款简易的摩斯编解码器。

2、编解码设计

　　自己玩儿，暂定中文摩斯编码。基本思想是，将汉字对应的四位区位码数字分别编码为数字对应的摩斯码，一个中文对应20位摩斯码。解码过程逆向。

3、代码实现

　　首先，项目结构图如下：

　　因为是个小工具，整个项目采用WPF实现。

主界面：

就核心过程而言，编码分两步：

1、汉字转区位码

 此算法是直接抄的，原始出处，有点儿懒得费功夫找了，再次声明，不是在下原创。

 /// <summary>
        /// 汉字转区位码方法
        /// </summary>
        /// <param name="chinese">汉字</param>
        /// <returns>区位码</returns>
        public static string ChineseToCoding(string chinese)
        {
            string pCode = "";
            byte[] pArray = new byte[2];
            pArray = Encoding.GetEncoding("GB2312").GetBytes(chinese);//得到汉字的字节数组
            int front = (short)(pArray[0] - ‘‘) - 160;//将字节数组的第一位160
            int back = (short)(pArray[1] - ‘‘) - 160;//将字节数组的第二位160
            pCode = front.ToString("D2") + back.ToString("D2");//再连接成字符串就组成汉字区位码
            return pCode;
        }

 

2、区位码转摩斯码

 

private static readonly Dictionary<string, string> _dictNumberMorse = new Dictionary<string, string>
        {
            { "0", "— — — — —"},
            { "1", "· — — — —"},
            { "2", "· · — — —"},
            { "3", "· · · — —"},
            { "4", "· · · · —"},
            { "5", "· · · · ·"},
            { "6", "— · · · ·"},
            { "7", "— — · · ·"},
            { "8", "— — — · ·"},
            { "9", "— — — — ·"},
        };

        private static readonly Dictionary<string, string> _dictMorseNumber = new Dictionary<string, string>
        {
            { "—————", "0"},
            { "·————", "1"},
            { "··———", "2"},
            { "···——", "3"},
            { "····—", "4"},
            { "·····", "5"},
            { "—····", "6"},
            { "——···", "7"},
            { "———··", "8"},
            { "————·", "9"},
        };

        public static string GBK2Morse(string gbkCode)
        {
            if (string.IsNullOrWhiteSpace(gbkCode) || gbkCode.Length != 4)
            {
                throw new ArgumentException($"{nameof(gbkCode)}非GBK区位码");
            }

            StringBuilder sbMorse = new StringBuilder();
            foreach (var s in gbkCode)
            {
                sbMorse.Append(_dictNumberMorse[s.ToString()]).Append("     ");
            }

            return sbMorse.ToString();
        }

 

4、运行效果 

github地址：https://github.com/KINGGUOKUN/MorseEncoder

5、结语

　　/     · · · · ·     · · · · ·     — — — — —     · · · — —     /     · · — — —     — — — — —     — — — · ·     · · · — —     /     · · — — —     — — — · ·     · · · · ·     — — — — —     /1024/     · · · — —     · — — — —     — — · · ·     — · · · ·     /     · · · — —     · · — — —     · · · · ·     · · · · —     /！

（大家猜出结语是啥了吗？）