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超级简易的JS计算器实例讲解(实现加减乘除)

2020-11-27 来源:易榕旅游

废话不多说,直接上代码

<!DOCTYPE html>
<html>
 <head>
 <meta charset="UTF-8">
 <title>简单的计算器</title>
 <style> 
 body{
 margin: 0;
 }
 .tab{
 border: 3px solid black ;
 border-radius: 2px;
 border-collapse:collapse;
 width: 268px;
 height: 402px;
 margin: 100px auto;
 }
 
 .tr{
 height: 67px;
 width: 268px;
 border: 3px solid black ;
 text-align: right;
 }
 .tr1{
 width: 268px;
 height: 67px;
 border: 3px solid black ;
 text-align: center;
 }
 .tr2{
 width: 67px;
 height: 67px;
 border: 3px solid black ;
 text-align: center;
 }
 
 
 </style>
 <script>
 
 var s1 = "";
 var s2 = "";
 var s3 = "";
 var s4 = "";
 var s5 = "";
 function view(val){
 var a = document.getElementById(val);
 s1 = a.innerHTML;
 if(s1=="+" || s1=="-" || s1=="*" || s1=="/"){
 s3 = s1;
 s1 = "";
 }
 
 if(s3=="+" || s3=="-" || s3=="*" || s3=="/"){
 add2(s1);
 
 }
 
 if(s3==""){
 add1(s1); 
 
 }
 
 
 
 
 }
 function add1(s1){
 s2 = s2 + s1;
 show();
 }
 function add2(s1){
 s4 = s4 + s1;
 show();
 }
 
 function cal(){
 switch(s3){
 case "+":{
 s5 = (String)((parseFloat(s2)+parseFloat(s4)).toFixed(2));
 result.innerHTML = s5;
 break;
 }
 case "-":{
 s5 = (String)((parseFloat(s2)-parseFloat(s4)).toFixed(2));
 result.innerHTML = s5;
 break;
 }
 case "*":{
 s5 = (String)((parseFloat(s2)*parseFloat(s4)).toFixed(2));
 result.innerHTML = s5;
 break;
 }
 case "/":{
 s5 = (String)((parseFloat(s2)/parseFloat(s4)).toFixed(2));
 result.innerHTML = s5;
 break;
 }
 }
 
 }
 
 function show(){
 var result = document.getElementById("result");
 
 result.innerHTML = s2+s3+s4;
 
 }
 
 
 
 </script>
 </head>
 <body>
 <table class="tab">
 <tr class = "tr2">
 <td colspan="4">简易计算器</td>
 </tr>
 <tr class="tr">
 <td id="result" colspan="4" > 
 
 </td>
 </tr>
 <tr >
 <td id="+" class="tr1" onclick="view('+')">+</td>
 <td id="-" class="tr1" onclick="view('-')">-</td>
 <td id="*" class="tr1" onclick="view('*')">*</td>
 <td id="/" class="tr1" onclick="view('/')">/</td>
 </tr>
 <tr >
 <td id="7" class="tr1" onclick="view('7')">7</td>
 <td id="8" class="tr1" onclick="view('8')">8</td>
 <td id="9" class="tr1" onclick="view('9')">9</td>
 <td id="0" class="tr1" onclick="view('0')">0</td>
 </tr>
 <tr>
 <td id="4" class="tr1" onclick="view('4')">4</td>
 <td id="5" class="tr1" onclick="view('5')">5</td>
 <td id="6" class="tr1" onclick="view('6')">6</td>
 <td id="." class="tr1" onclick="view('.')">.</td>
 </tr>
 <tr>
 <td id="1" class="tr1" onclick="view('1')">1</td>
 <td id="2" class="tr1" onclick="view('2')">2</td>
 <td id="3" class="tr1" onclick="view('3')">3</td>
 <td id="=" class="tr1" onclick="cal()" >=</td>
 </tr>
 </table>
 </body>
</html>

对于这个程序来说,判断的顺序非常重要,不然就会把"+"号存在s2,s4中而不是s3中。

以上这篇超级简易的JS计算器实例讲解(实现加减乘除)就是小编分享给大家的全部内容了,希望能给大家一个参考,也希望大家多多支持脚本之家。

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