乘风原创程序

  • javascript代码实现简易计算器
  • 2021/1/25 8:24:12
  • 本文实例为大家分享了javascript实现简易计算器的具体代码,供大家参考,具体内容如下

    编辑了几个小时研发了一个简易好理解的计算器。不停改Bug,终于改好了。

    这是样式

    这是Css部分

    <style>
      #box {
       background-image: linear-gradient(120deg, #84fab0 0%, #8fd3f4 100%);
       width: 500px;
       height: 420px;
       margin: auto;
       margin-top: 200px;
       position: relative;
      }
    
      .reckon {
       width: 280px;
       height: 200px;
       background-image: linear-gradient(120deg, #d4fc79 0%, #96e6a1 100%);
       ;
       position: absolute;
       top: 100px;
       left: 100px;
       border: 5px solid #2a2b2c
      }
    
      #input1 {
       background-image: linear-gradient(to top, #cfd9df 0%, #e2ebf0 100%);
       border: none;
       width: 220px;
       height: 8px;
       float: right;
       margin-top: 10px;
       margin-right: 20px;
       outline: none;
       padding: 10px
      }
    
      ul li {
       float: left;
       list-style: none;
       margin: 4px 2px;
       border-radius: 3px;
       background-image: linear-gradient(120deg, #a1c4fd 0%, #c2e9fb 100%);
       box-shadow: 2px 2px #ccc;
       color: #fff;
       font-weight: "楷体";
       width: 50px;
       height: 30px;
       text-align: center;
       line-height: 30px;
      }
    
      ul {
       margin-top: 5px;
      }
    
      ul li:hover {
       opacity: 0.7;
      }
    </style>

    这是HTML部分

    <div id="box">
      <div class="reckon" id="reckon">
       <input type="text" id="input1">
       <ul>
        <li class="num">7</li>
        <li class="num">8</li>
        <li class="num">9</li>
        <li class="opcr">+</li>
    
        <li class="num">4</li>
        <li class="num">5</li>
        <li class="num">6</li>
        <li class="opcr">- </li>
    
        <li class="num">1</li>
        <li class="num">2</li>
        <li class="num">3</li>
        <li class="opcr">*</li>
    
        <li class="num">0</li>
        <li id="returnZero">C</li>
        <li id="resule">=</li>
        <li class="opcr">/</li>
       </ul>
      </div>
    
    
     </div>
    /* 定义两个标签来存放符号跟第一个值*/
     <input type="text" id="text1" style="display:none">
     <input type="text" id="per" style="display:none">

    html部分的话就是吧所有数字定义为一个class名字,把所有运算符号定义为一个class 以及定义两个input来存放运算符

    <script>
      lis = document.querySelectorAll("#box ul .num")//获取所有的数字
      opcr = document.querySelectorAll("#box ul .opcr")//获取运算符
      for (var i = 0; i < lis.length; i++) { //遍历所有的数字
       lis[i].onclick = function () {
        input1.value += parseInt(this.innerHTML)//点击input1显示
       }
      }
      //遍历所有的运算符
      for (let i = 0; i < opcr.length; i++) {
       opcr[i].onclick = function () {
        if (text1.value == "") {//当存放第一个值为空时候
         text1.value = input1.value//存放第一个值
         input1.value = ""   //input框里的值为空
         per.value = this.innerHTML; //存放符号的值为空
        } else {
         text1.value = eval(text1.value + per.value + input1.value)//不是空的时候 计算
         per.value = this.innerHTML;//存放符号的值为点击的值
         input1.value = ""//input框里的值为空
        }
       }
      }
      //等于
      resule.onclick = function () {
       input1.value = eval(text1.value + per.value + input1.value)//计算里面的值
       per.value = "" //清空存放per的值
       text1.value = ""//input框里的值为空
    
      }
      //点击清空所有
      returnZero.onclick = function () {
       input1.value = ""
       per.value = ""
       text1.value = ""
      }
    </script>

    完整部分

    <!DOCTYPE html>
    <html lang="en">
    <head>
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <meta http-equiv="X-UA-Compatible" content="ie=edge">
     <title>简易计算器</title>
     <style>
      #box {
       background-image: linear-gradient(120deg, #84fab0 0%, #8fd3f4 100%);
       width: 500px;
       height: 420px;
       margin: auto;
       margin-top: 200px;
       position: relative;
      }
    
      .reckon {
       width: 280px;
       height: 200px;
       background-image: linear-gradient(120deg, #d4fc79 0%, #96e6a1 100%);
       ;
       position: absolute;
       top: 100px;
       left: 100px;
       border: 5px solid #2a2b2c
      }
    
      #input1 {
       background-image: linear-gradient(to top, #cfd9df 0%, #e2ebf0 100%);
       border: none;
       width: 220px;
       height: 8px;
       float: right;
       margin-top: 10px;
       margin-right: 20px;
       outline: none;
       padding: 10px
      }
    
      ul li {
       float: left;
       list-style: none;
       margin: 4px 2px;
       border-radius: 3px;
       background-image: linear-gradient(120deg, #a1c4fd 0%, #c2e9fb 100%);
       box-shadow: 2px 2px #ccc;
       color: #fff;
       font-weight: "楷体";
       width: 50px;
       height: 30px;
       text-align: center;
       line-height: 30px;
      }
    
      ul {
       margin-top: 5px;
      }
    
      ul li:hover {
       opacity: 0.7;
      }
     </style>
    </head>
    
    <body>
     <div id="box">
      <div class="reckon" id="reckon">
       <input type="text" id="input1">
       <ul>
        <li class="num">7</li>
        <li class="num">8</li>
        <li class="num">9</li>
        <li class="opcr">+</li>
    
        <li class="num">4</li>
        <li class="num">5</li>
        <li class="num">6</li>
        <li class="opcr">- </li>
    
        <li class="num">1</li>
        <li class="num">2</li>
        <li class="num">3</li>
        <li class="opcr">*</li>
    
        <li class="num">0</li>
        <li id="returnZero">C</li>
        <li id="resule">=</li>
        <li class="opcr">/</li>
       </ul>
      </div>
    
    
     </div>
    
     <input type="text" id="text1" style="display:block">
     <input type="text" id="per" style="display:block">
    
     <script>
      lis = document.querySelectorAll("#box ul .num")//获取所有的数字
      opcr = document.querySelectorAll("#box ul .opcr")//获取+——*/
      for (var i = 0; i < lis.length; i++) { //遍历所有的数字
       lis[i].onclick = function () {
        input1.value += parseInt(this.innerHTML)//点击input1显示
       }
      }
    
      //遍历所有的+——*/
      for (let i = 0; i < opcr.length; i++) {
       opcr[i].onclick = function () {
        if (text1.value == "") {//当存放第一个值为空时候
         text1.value = input1.value//存放第一个值
         input1.value = ""   //input框里的值为空
         per.value = this.innerHTML; //存放符号的值为空
        } else {
         text1.value = eval(text1.value + per.value + input1.value)//不是空的时候 计算值
         per.value = this.innerHTML;//存放符号的值为点击的值
         input1.value = ""//input框里的值为空
        }
       }
      }
      //等于
      resule.onclick = function () {
       input1.value = eval(text1.value + per.value + input1.value)//计算里面的值
       per.value = "" //清空存放per的值
       text1.value = ""//input框里的值为空
    
      }
      //点击清空所有
      returnZero.onclick = function () {
       input1.value = ""
       per.value = ""
       text1.value = ""
      }
     </script>
    </body>
    </html>