JS实现多功能计算器

时间：2021-05-26

本文实例为大家分享了JS实现多功能计算器的具体代码，供大家参考，具体内容如下

1、开发语言 HTML+CSS+JavaScript

2、开发工具 Visual Studio Code

3、项目GitHub地址：计算器 (喜欢可以给一个star)

4、项目运行截图：

5、技术分析：由于除了简单的四则运算，还需要进行括号匹配，以及优先级的运算。采用后缀表达式的形式进行处理，同时通过模拟栈的特点运用JS自带的数组进行处理。由于代码有详细的注释，所以直接上代码。

6、项目代码：

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\计算器\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>计算器</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="回退一位数" 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\计算器\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;//回退一个文字 if(number === 'D') { text = text.substring(0,text.length-1); document.getElementById('display').innerHTML=text; return; }//判断第一个数字是不是运算符 else if(judgeBegin(number) && text == "") return;//判断是否是连续两个运算符一起输入 else if(judgeBegin(number) && judgeNext(text,number) && text[text.length-1] !== ')') return;//判断第一个输入是不是‘.'，如果是变为0. else if(number === '.' && text == "") number = "0.";//如果输入归0，清空输入 else if(number === 'C') { document.getElementById('text').innerHTML=""; document.getElementById('display').innerHTML=""; return; }//输入是等号就判断 else if(number === '=') { //将数字与运算符分开 let array = []; let n = text.length; for(let i = 0; i < n; i++) { var JudgeNumber = true; let res = ""; //判断第一个数字是否是负号 if(i===0 && text[i] === '-') { res+=text[i]; i++; } //判断是不是在运算符之后的减号，是就变为负号 if(i !== 0 && near(array[array.length-1]) && text[i] === '-') { res+=text[i]; i++; } //判断是否为连续的数字 while(JudgeIsNumber(text[i]) && i < n) { res += text[i]; i++; JudgeNumber = false; } //如果不为数字了要回退一个 if(JudgeNumber === false) i--; //判断其他运算符 if(JudgeNumber === true) if(judgeBegin(text[i]) || text[i] === '(' || text[i] === '-' || text[i] === ')') res+=text[i]; array.push(res); } // console.log(array); //中缀表达式变为后缀表达式 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;}//判断是不是运算符function judgeBegin(number){ for(let i = 0; i < ysf.length; i++) { if(ysf[i] === '-') continue; if(ysf[i] === number) return true; } return false;}//判断是否输入两个连续的运算符function judgeNext(text,number){ if(number === '-') return; let a = text.length; if(judgeBegin(text[a-1]) && judgeBegin(number)) return true; return false;}//判断输入的字符里面是不是数字function JudgeIsNumber(number){ for(let i = 0; i < isNumber.length; i++) { if(isNumber[i] === number) return true; } return false;}//判断减号前面是否有别的运算符从而确定是不是负号function near(number){ for(let i = 0; i < sizeyunsuan.length; i++) { if(sizeyunsuan[i] === number) return true; } return false;}//中缀表达式改为后缀表达式function houZhui(array){ var stack = []; var textArea = []; for(let i = 0; i < array.length; i++) { if(near(array[i]) || array[i] === ')') { //如果是空直接入栈 if(stack.length === 0) stack.push(array[i]); //如果栈顶为左括号直接入栈 else if(stack[stack.length-1] === '(' && array[i] !== ')') stack.push(array[i]); //如果输入左括号直接入栈 else if(array[i] === '(') stack.push(array[i]); //如果输入的是右括号 else if(array[i] === ')') { //一直弹出直到遇到左括号 while(stack[stack.length-1] !== '(') { let a = stack.pop(); textArea.push(a); } //弹出左括号 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;}//计算后缀表达式function compute(array){ var NUMBER = []; for(let i = 0; i < array.length; i++) { //是运算符就计算 if(near(array[i])){ //加法 if(array[i] === '+') { if(NUMBER.length < 2) return "错误"; else { let a = NUMBER.pop(); let b = NUMBER.pop(); let c = a + b; NUMBER.push(c); } } //减法 else if(array[i] === '-') { if(NUMBER.length < 2) return "错误"; 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 "错误"; 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 "错误"; else { let a = NUMBER.pop(); let b = NUMBER.pop(); if(a === 0) return "0不能作为除数"; 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 "错误"; else { let b = String(NUMBER[0]); return b; }}

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