其他
【每日一练】72—用Javascript 写一个计算器小项目
写在前面
今天练习这个小项目是用Javascript实现的一个计算器,这个练习也是我们在学习JavaScript时候会经常出现的一个练习。
关于这个计算器的练习,我之前在视频号上也分享过一个,具体如下:
今天的这个效果,跟之前的也类似,不过今天这个练习增加了一个暗模式,具体的可以看下面的最终效果:
<!doctype html>
<html>
<head>
<title>【每日一练】72—用Javascript写一个计算器小项目</title>
</head>
<body>
<div class="toggleBtn"></div>
<div class="calculator">
<div class="buttons">
<h2 id="value"></h2>
<span id="clear">Clear</span>
<span>/</span>
<span>*</span>
<span>7</span>
<span>8</span>
<span>9</span>
<span>-</span>
<span>4</span>
<span>5</span>
<span>6</span>
<span id="plus">+</span>
<span>1</span>
<span>2</span>
<span>3</span>
<span>0</span>
<span>00</span>
<span>.</span>
<span id="equal">=</span>
</div>
</div>
<script>
let buttons = document.querySelector(".buttons");
let btn = buttons.querySelectorAll("span");
let value = document.getElementById("value");
let toggleBtn = document.querySelector('.toggleBtn')
let body = document.querySelector('body')
for(let i=0; i<btn.length; i++){
btn[i].addEventListener("click", function () {
if(this.innerHTML=="="){
value.innerHTML = eval(value.innerHTML);
}else{
if(this.innerHTML=='clear'){
value.innerHTML = "";
}
else{
value.innerHTML += this.innerHTML;
}
}
});
}
toggleBtn.onclick = function(){
body.classList.toggle('dark')
}
</script>
</body>
</html>
*
{
margin: 0;
padding: 0;
box-sizing: border-box;
font-family: consolas;
}
body
{
display: flex;
justify-content: center;
align-items: center;
min-height: 100vh;
background: #edf1f4;
}
.calculator
{
position: relative;
width: 340px;
padding: 20px;
border-radius: 20px;
box-shadow: 15px 15px 20px rgba(0,0,0,0.1),
-15px -15px 20px #fffb;
}
.calculator .buttons
{
position: relative;
display: grid;
}
.calculator .buttons #value
{
position: relative;
left: 8px;
grid-column: span 4;
height: 100px;
line-height: 100px;
padding: 0 20px;
border-radius: 10px;
text-align: end;
font-size: 2em;
margin-bottom: 12px;
color: #5166d6;
overflow: hidden;
font-weight: 500;
width: calc(100% - 16px);
user-select: none;
box-shadow: inset 5px 5px 10px rgba(0,0,0,0.1),
inset -5px -5px 20px #fff;
}
.calculator .buttons span
{
position: relative;
display: flex;
justify-content: center;
align-items: center;
padding: 10px;
border-radius: 10px;
margin: 10px;
min-width: 40px;
font-size: 1.2em;
color: #666;
font-weight: 700;
border: 2px solid #edf1f4;
box-shadow: 5px 5px 10px rgba(0,0,0,0.1),
-5px -5px 10px #fff;
cursor: pointer;
user-select: none;
}
.calculator .buttons span:active
{
color: #f44336;
box-shadow: inset 5px 5px 10px rgba(0,0,0,0.1),
inset -5px -5px 10px #fff;
}
.calculator .buttons span#clear
{
grid-column: span 2;
background: #f44336;
border: 2px solid #edf1f4;
color: #fff;
}
.calculator .buttons span#plus
{
grid-row: span 2;
background: #31a935;
border: 2px solid #edf1f4;
color: #fff;
}
.calculator .buttons span#equal
{
grid-row: span 2;
background: #2196f3;
border: 2px solid #edf1f4;
color: #fff;
}
.calculator .buttons span#clear:active,
.calculator .buttons span#plus:active,
.calculator .buttons span#equal:active
{
box-shadow: 5px 5px 10px rgba(0,0,0,0.1),
-5px -5px 10px #fff,
inset 5px 5px 10px rgba(0,0,0,0.1);
}
.toggleBtn
{
position: fixed;
top: 20px;
right: 20px;
background: #555;
width: 20px;
height: 20px;
border-radius: 50%;
cursor: pointer;
border: 2px solid #edf1f4;
box-shadow: 5px 5px 10px rgba(0,0,0,0.1),
-5px -5px 10px #fff;
}
.dark .toggleBtn
{
background: #edf1f4;
border: 2px solid #333;
box-shadow: 5px 5px 10px rgba(0,0,0,0.5),
-5px -5px 10px rgba(255,255,255,0.25);
}
.dark
{
background: #282c2f;
}
.dark .calculator
{
background: #33393e;
box-shadow: 15px 15px 20px rgba(0,0,0,0.25),
-15px -15px 20px rgba(255,255,255,0.1);
}
.dark .calculator #value
{
color: #eee;
box-shadow: inset 5px 5px 10px rgba(0,0,0,0.5),
inset -5px -5px 20px rgba(255,255,255,0.1);
}
.dark .calculator .buttons span
{
color: #eee;
border: 2px solid #333;
box-shadow: 5px 5px 10px rgba(0,0,0,0.25),
-5px -5px 10px rgba(255,255,255,0.1);
}
.dark .calculator .buttons span:active
{
box-shadow: inset 5px 5px 10px rgba(0,0,0,0.25),
inset -5px -5px 10px rgba(255,255,255,0.1);
}
.dark .calculator .buttons span#clear,
.dark .calculator .buttons span#plus,
.dark .calculator .buttons span#equal
{
border: 2px solid #333;;
}
.dark .calculator .buttons span#clear:active,
.dark .calculator .buttons span#plus:active,
.dark .calculator .buttons span#equal:active
{
box-shadow: inset 5px 5px 10px rgba(0,0,0,0.1);
}
写在最后
今天的JavaScript代码是直接嵌在HTML代码里的,没有再单独写一个JavaScript文件了,如果你想单独写一个JavaScript文件也是可以的,请大家根据自己的情况来即可。
好了,我们今天的【每日一练】的全部内容就到这里结束了,希望今天的小练习对你有用,如果你觉得有帮助的话,请点赞我,关注我,并将它分享给你身边做开发的朋友,也许能够帮助到他。
我是杨小爱,我们明天见。
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