JS實現(xiàn)多功能計算器

更新時間：2020年10月28日 15:33:35 作者：烯烴@

這篇文章主要為大家詳細介紹了JS實現(xiàn)多功能計算器，文中示例代碼介紹的非常詳細，具有一定的參考價值，感興趣的小伙伴們可以參考一下

本文實例為大家分享了JS實現(xiàn)多功能計算器的具體代碼，供大家參考，具體內(nèi)容如下

1、開發(fā)語言 HTML+CSS+JavaScript

2、開發(fā)工具 Visual Studio Code

3、項目GitHub地址：計算器 (喜歡可以給一個star)

4、項目運行截圖：

5、技術(shù)分析：由于除了簡單的四則運算，還需要進行括號匹配，以及優(yōu)先級的運算。采用后綴表達式的形式進行處理，同時通過模擬棧的特點運用JS自帶的數(shù)組進行處理。由于代碼有詳細的注釋，所以直接上代碼。

6、項目代碼：

compute.html：

<!--
 * @Author: CSU_XZY
 * @Date: 2020-10-15 21:17:33
 * @LastEditors: CSU_XZY
 * @LastEditTime: 2020-10-16 22:07:08
 * @FilePath: \第二天\計算器\compute.html
 * @Description: just to play
-->
<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="UTF-8">
 <meta name="viewport" content="width=device-width, initial-scale=1.0">
 <title>計算器</title>
</head>
<style>
 *{
  margin: 0;
  padding: 0;
 }
 body{
  background-color: #FCFDFE;
 }
 .container{
  overflow: hidden;
  box-shadow: 0 0 3px 0 rgba(0, 0, 0, .3);
  margin: 150px auto;
  width: 548px;
  height: 274px;
  background-color: #fff;
 }
 .box{
  background-color: #fcfdff;
  margin: 15px auto;
  overflow: hidden;
  width: 514px;
  height: 244px;
 }
 .number{
  width: 514px;
  height: 189px;
 }
 .text{
  width: 514px;
  height: 55px;
  margin: 0;
 }
 span{
  border-top: solid 1px #ebebeb;
  border-right: solid 1px #ebebeb;
  box-sizing: border-box;
  float: left;
  display: block;
  width: 25%;
  font-size: 16px;
  color: #333;
  background-color: #fff;
  line-height: 37px;
  cursor: pointer;
  text-align: center;
  font-weight: 10px;
 }
 span:hover{
  background-color: #d3d7d4;
 }
 span:active{
  background-color: #afdfe4;
  
 }
 
 .text>p{
  text-align: right;
  width: 514px;
  height: 24px;
  line-height: 25px;
  font-size: 25px;
 }
 .number>div{
  width: 514px;
  height: 37.8px;
 }
 .around{
  background-color: #f9f9f9;
  color: #f60;
 }
 .compute{
  color: #333;
 }
 .bottom{
  background-color: #fff;
  color: #f60;
 }
 .dot{
  font-size: 23px; 
  font-weight: 19px;
 }
</style>
<body>
 <div class="container">
  <div class="box">
   <div class="text">
    <p id="text"></p>
    <p id="display"></p>
   </div>
   <div class="number">
    <div class="around">
     <span onclick="showDetails(this)" data-value="(" class="around">(</span>
     <span onclick="showDetails(this)" data-value=")" class="around">)</span>
     <span onclick="showDetails(this)" data-value="D" title="回退一位數(shù)" class="around">del</span>
     <span onclick="showDetails(this)" data-value="C" class="around compute">C</span>
    </div>
    <div>
     <span onclick="showDetails(this)" data-value="7">7</span>
     <span onclick="showDetails(this)" data-value="8">8</span>
     <span onclick="showDetails(this)" data-value="9">9</span>
     <span onclick="showDetails(this)" data-value="÷" class="around">÷</span>
    </div>
    <div>
     <span onclick="showDetails(this)" data-value="4">4</span>
     <span onclick="showDetails(this)" data-value="5">5</span>
     <span onclick="showDetails(this)" data-value="6">6</span>
     <span onclick="showDetails(this)" data-value="x" class="around">x</span>
    </div>
    <div>
     <span onclick="showDetails(this)" data-value="1">1</span>
     <span onclick="showDetails(this)" data-value="2">2</span>
     <span onclick="showDetails(this)" data-value="3">3</span>
     <span onclick="showDetails(this)" data-value="-" class="around">-</span>
    </div>
    <div>
     <span onclick="showDetails(this)" data-value="0">0</span>
     <span onclick="showDetails(this)" data-value="." class="around bottom dot">.</span>
     <span onclick="showDetails(this)" data-value="=" class="around bottom">=</span>
     <span onclick="showDetails(this)" data-value="+" class="around">+</span>
    </div>
   </div>
  </div>
 </div>
</body>
<script type="text/javascript" src="compute.js"></script>
</html>

compute.js:

/*
 * @Author: CSU_XZY
 * @Date: 2020-10-15 21:17:45
 * @LastEditors: CSU_XZY
 * @LastEditTime: 2020-10-17 00:04:41
 * @FilePath: \第二天\計算器\compute.js
 * @Description: just to play
 */
var ysf = ['+','÷','=',')','%','x','-','D'];
var sizeyunsuan = ['+','÷','(','x','-'];
var isNumber = ['1','2','3','4','5','6','7','8','9','0','.'];


function showDetails(number)
{
 var number = number.getAttribute("data-value");
 var text = document.getElementById('display').innerText;
//回退一個文字
 if(number === 'D')
 {
  text = text.substring(0,text.length-1);
  document.getElementById('display').innerHTML=text;
  return;
 }
//判斷第一個數(shù)字是不是運算符
 else if(judgeBegin(number) && text == "")
 return;
//判斷是否是連續(xù)兩個運算符一起輸入
 else if(judgeBegin(number) && judgeNext(text,number) && text[text.length-1] !== ')')
 return;
//判斷第一個輸入是不是‘.'，如果是變?yōu)?.
 else if(number === '.' && text == "")
 number = "0.";
//如果輸入歸0，清空輸入
 else if(number === 'C')
 {
  document.getElementById('text').innerHTML="";
  document.getElementById('display').innerHTML="";
  return;
 }
//輸入是等號就判斷
 else if(number === '=')
 {
  //將數(shù)字與運算符分開
  let array = [];
  let n = text.length;
  for(let i = 0; i < n; i++)
  {
   var JudgeNumber = true;
   let res = "";
   //判斷第一個數(shù)字是否是負號
   if(i===0 && text[i] === '-')
   {
    res+=text[i];
    i++;
   }
   //判斷是不是在運算符之后的減號，是就變?yōu)樨撎?
   if(i !== 0 && near(array[array.length-1]) && text[i] === '-')
   {
    res+=text[i];
    i++;
   }
   //判斷是否為連續(xù)的數(shù)字
   while(JudgeIsNumber(text[i]) && i < n)
   {
    res += text[i];
    i++;
    JudgeNumber = false;
   }
   //如果不為數(shù)字了要回退一個
   if(JudgeNumber === false)
   i--;
   //判斷其他運算符
   if(JudgeNumber === true)
   if(judgeBegin(text[i]) || text[i] === '(' || text[i] === '-' || text[i] === ')')
   res+=text[i];
   array.push(res);
  }
  //
   console.log(array);
  //中綴表達式變?yōu)楹缶Y表達式
  var hz = houZhui(array);
  console.log(hz);
  var result = compute(hz);
  document.getElementById('text').innerHTML = text;
  document.getElementById('display').innerHTML = result;
  return;
 }
 text+=number;
 document.getElementById('display').innerHTML=text;
}

//判斷是不是運算符
function judgeBegin(number)
{
 for(let i = 0; i < ysf.length; i++)
 {
  if(ysf[i] === '-')
  continue;
  if(ysf[i] === number)
  return true;
 }
 return false;
}

//判斷是否輸入兩個連續(xù)的運算符
function judgeNext(text,number)
{
 if(number === '-')
 return;
 let a = text.length;
 if(judgeBegin(text[a-1]) && judgeBegin(number))
 return true;
 return false;
}

//判斷輸入的字符里面是不是數(shù)字
function JudgeIsNumber(number){
 for(let i = 0; i < isNumber.length; i++)
 {
  if(isNumber[i] === number)
  return true;
 }
 return false;
}

//判斷減號前面是否有別的運算符從而確定是不是負號
function near(number)
{
 for(let i = 0; i < sizeyunsuan.length; i++)
 {
  if(sizeyunsuan[i] === number)
  return true;
 }
 return false;
}

//中綴表達式改為后綴表達式
function houZhui(array)
{
 var stack = [];
 var textArea = [];
 for(let i = 0; i < array.length; i++)
 {
  if(near(array[i]) || array[i] === ')')
  {
   //如果是空直接入棧
   if(stack.length === 0)
   stack.push(array[i]);
   //如果棧頂為左括號直接入棧
   else if(stack[stack.length-1] === '(' && array[i] !== ')')
   stack.push(array[i]);
   //如果輸入左括號直接入棧
   else if(array[i] === '(')
   stack.push(array[i]);
   //如果輸入的是右括號
   else if(array[i] === ')')
   {
    //一直彈出直到遇到左括號
    while(stack[stack.length-1] !== '(')
    {
     let a = stack.pop();
     textArea.push(a);
    }
    //彈出左括號
    stack.pop();
   }
   else if(array[i] === '-' || array[i] === '+')
   {
    while(stack[stack.length-1] !== '(' && stack.length !== 0)
    {
     let a = stack.pop();
     textArea.push(a);
    }
    stack.push(array[i]);
   }
   else if(array[i] === 'x' || array[i] === '÷')
   {
    while(stack[stack.length-1] !== '(' && stack[stack.length-1] !== '+' && stack[stack.length-1] !== '-' && stack.length !== 0)
    {
     let a = stack.pop();
     textArea.push(a);
    }
    stack.push(array[i]);
   }
  }
  else{
   textArea.push(array[i])
  }
 }
 while(stack.length !== 0)
 {
  let a = stack.pop();
  textArea.push(a);
 }
 return textArea;
}

//計算后綴表達式
function compute(array){
 var NUMBER = [];
 for(let i = 0; i < array.length; i++)
 {
  //是運算符就計算
  if(near(array[i])){
   //加法
   if(array[i] === '+')
   {
    if(NUMBER.length < 2)
    return "錯誤";
    else
    {
     let a = NUMBER.pop();
     let b = NUMBER.pop();
     let c = a + b;
     NUMBER.push(c);
    }
   }
   //減法
   else if(array[i] === '-')
   {
    if(NUMBER.length < 2)
    return "錯誤";
    else
    {
     let a = NUMBER.pop();
     let b = NUMBER.pop();
     let c = b - a;
     NUMBER.push(c);
    }
   }
   //乘法
   else if(array[i] === 'x')
   {
    if(NUMBER.length < 2)
    return "錯誤";
    else
    {
     let a = NUMBER.pop();
     let b = NUMBER.pop();
     let c = a * b;
     NUMBER.push(c);
    }
   }
   //除法
   else if(array[i] === '÷')
   {
    if(NUMBER.length < 2)
    return "錯誤";
    else
    {
     let a = NUMBER.pop();
     let b = NUMBER.pop();
     if(a === 0)
     return "0不能作為除數(shù)";
     let c = b / a;
     NUMBER.push(c);
    }
   }
  }
  else{
   if(array[i][0] === '-')
   {
    let temp = array[i].substring(1,array[0].length);
    let num = parseFloat(temp);
    num = -num;
    NUMBER.push(num);
   }
   else{
    let num = parseFloat(array[i]);
    NUMBER.push(num);
   }
   console.log(NUMBER);
  }
 }
 if(NUMBER.length !== 1)
 return "錯誤";
 else
 {
  let b = String(NUMBER[0]);
  return b;
 }
}

以上就是本文的全部內(nèi)容，希望對大家的學習有所幫助，也希望大家多多支持腳本之家。

您可能感興趣的文章: