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> <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>
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。
