请问老师 代码还可以压缩点吗?
来源:7-2 编程练习
慕前端2064318
2019-10-24 18:45:17
<!DOCTYPE html>
<html>
<head>
<title></title>
<style type="text/css">
html,
body {
margin: 0;
padding: 0;
}
div:not(:nth-of-type(2)) {
width: 500px;
min-height: 100%;
background-color: #a0e4ff;
padding: 30px;
margin: 0 auto;
text-align: center;
}
/*ul默认有外边距*/
ul {
width: 300px;
height: 100%;
background-color: #ecc7ea;
list-style: none;
/*清除默认边距*/
margin: 0;
padding: 0;
margin: 20px auto;
margin-bottom: 30px;
padding: 10px;
}
li {
width: 200px;
height: 30px;
line-height: 30px;
margin: 30px auto;
background-color: #cdffc0;
}
button {
width: 140px;
height: 30px;
background-color: #ededee;
border-radius: 5px;
outline: none;
border: 1px #777 solid;
margin: 0px 10px;
}
</style>
</head>
<body>
<div id="box">
<button id="btnAdd">添加元素</button>
<button id="btnRemove">删除元素</button>
<ul id="list">
我是ul
<li>我是li1</li>
<li>我是li2</li>
<li>我是li3</li>
</ul>
</div>
<script type="text/javascript">
// 此处填写代码;
var btnAdd = document.querySelector('#btnAdd');
var btnRemove = document.querySelector('#btnRemove');
var list = document.querySelector('#list');
btnAdd.onclick = function() {
var items = list.querySelectorAll('li');
var createLi = document.createElement('li');
createLiText = document.createTextNode('我是li' + (items.length + 1));
createLi.appendChild(createLiText);
list.appendChild(createLi);
window.items = items;
changeColor();
};
btnRemove.onclick = function() {
var items = list.querySelectorAll('li');
list.removeChild(items[items.length - 1]);
};
function changeColor() {
var items = list.querySelectorAll('li');
for (let index = 0; index < items.length; index++) {
const element = items[index];
element.onmouseover = function() {
element.style.backgroundColor = 'red';
};
element.onmouseout = function() {
element.style.backgroundColor = '#fff';
};
}
}
changeColor();
console.log(project);
// console.log(items);
// console.log(createLi);
</script>
</body>
</html>
1回答
好帮手慕夭夭
2019-10-24
你好同学,做的很不错。另外,全局变量和全局属性类似,所以没有必要定义成局部变量,再把它赋值给全局属性。如下优化:
祝学习愉快,望采纳。
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