Build a JavaScript Calculator
A Simple Calculator
目标: 在 CodePen.io 上做一个类似于 FreeCodeCamp Calculator 的APP。
功能：可以对两个数字进行加、减、乘、除的运算。
功能: 可以使用清除按钮清空当前的所有输入内容.
功能: 可以把多个运算连接起来操作, 直到按下等号键, 计算器输出正确的运算结果.
代码如下：
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<meta http-equiv="content-type" content="text/html"; charset="utf-8" >
<title>A Simple Calculator</title>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.0/jquery.min.js"></script>
<script type="text/javascript" src="01.js"></script>
<link rel="stylesheet" type="text/css" media="screen" href="01.css">
</head>
<body>
<div class="calculator">
<p class="title">A Simple Calculator</p>
<div class="top">
<button id="clear" value="C">C</button>
<input type="textbox" class="textbox" readonly>
<div class="clearboth"></div>
</div>
<div class="buttons">
<button value="7">7</button>
<button value="8">8</button>
<button value="9">9</button>
<button class="operator" value="+">+</button>
<button value="4">4</button>
<button value="5">5</button>
<button value="6">6</button>
<button class="operator" value="-">-</button>
<button value="1">1</button>
<button value="2">2</button>
<button value="3">3</button>
<button class="operator" value="/">÷</button>
<button value="0">0</button>
<button value=".">.</button>
<button id="eval" value="=">=</button>
<button class="operator" value="*">x</button>
</div>
<div class="clearboth"></div>
</div>
</body>CSS
* {
margin: 0;
padding: 0;
box-sizing: border-box;
font: bold 14px Arial, sans-serif;
}
body {
height: 100%;
background: white;
background: radial-gradient(circle, #fff 20%, #ccc);
background-size: cover;
}
.calculator {
width: 325px;
height: auto;
margin: 100px auto;
padding: 20px 20px 9px;
background: #9dd2ea;
background: linear-gradient(#9dd2ea, #8bceec);
border-radius: 3px;
box-shadow: 0px 4px #009de4, 0px 10px 15px rgba(0, 0, 0, .2);
}
#clear {
float: left;
}
.title {
font-size: 20px;
font-family: 'Oleo Script', cursive;
color: #F19953;
margin: 0px 10px 20px;
text-align: center;
}
.textbox {
border: none;
height: 40px;
width: 212px;
float: right;
padding: 0 10px;
background: rgba(0, 0, 0, 0.2);
border-radius: 3px;
box-shadow: inset 0px 4px rgba(0, 0, 0, 0.2);
font-size: 17px;
line-height: 40px;
color: white;
text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.2);
text-align: right;
letter-spacing: 1px;
}
.clearboth {
clear: both;
}
button {
border: none;
width: 66px;
height: 36px;
float: left;
position: relative;
top: 0;
background: white;
border-radius: 3px;
box-shadow: 0px 4px rgba(0, 0, 0, 0.2);
margin: 0 7px 11px 0;
color: #888;
line-height: 36px;
text-align: center;
user-select: none;
transition: all 0.2s ease;
}
.operator {
background: #FFF0F5;
margin-right: 0;
}
#eval {
background: #f1ff92;
box-shadow: 0px 4px #9da853;
color: #888e5f;
}
#clear {
background: #ff9fa8;
color: white;
box-shadow: 0px 4px #ff7c87;
}
.buttons button:hover {
background: #9c89f6;
box-shadow: 0px 4px #6b54d3;
color: white;
}
#eval:hover {
background: #abb850;
box-shadow: 0px 4px #717a33;
color: #ffffff;
}
#clear:hover {
background: #f68991;
box-shadow: 0px 4px #d3545d;
color: white;
}
.buttons button:active {
box-shadow: 0px 0px #6b54d3;
top: 4px;
}
#eval:active {
box-shadow: 0px 0px #717a33;
top: 4px;
}
#clear:active {
top: 4px;
box-shadow: 0px 0px #d3545d;
}Javascript
var ans = "";
var clear = false;
var calc = "";
$(document).ready(function() {
$("button").click(function() {
var text = $(this).attr("value");
if(parseInt(text, 10) == text || text === "." || text === "/" || text === "*" || text === "-" || text === "+") {
if(clear === false) {
calc += text;
$(".textbox").val(calc);
} else {
calc = text;
$(".textbox").val(calc);
clear = false;
}
} else if(text === "C") {
calc = "";
$(".textbox").val("");
} else if(text === "=") {
ans = eval(calc);
$(".textbox").val(ans);
clear = true;
}
});
});All Javascript Project
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