批改状态:未批改
老师批语:
1.foreach如何进行遍历
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>foreach</title>
</head>
<body>
<ul>
<li>01</li>
<li>02</li>
<li>03</li>
<li>04</li>
<li>05</li>
<li>06</li>
<li>07</li>
<li>08</li>
</ul>
<script>
var lis = document.getElementsByTagName('li');
var arr = Array.prototype.slice.call(lis);
arr.forEach(function (value,key) {
if (key % 2 === 0)
value.style.background = 'lightgray';
})
</script>
</body>
</html>点击 "运行实例" 按钮查看在线实例
foreach遍历要对应类似于数组的格式,类似于无序列表这种,第一步通过页面内的li标签抓取数据,第二步转换对象为数组,之后再使用foreach进行遍历
2.使用splice进行增删改
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>foreach</title>
</head>
<body>
<ul>
<li>01</li>
<li>02</li>
<li>03</li>
<li>04</li>
<li>05</li>
<li>06</li>
<li>07</li>
<li>08</li>
</ul>
<script>
var lis = document.getElementsByTagName('li');
var arr = Array.prototype.slice.call(lis);
arr.splice(2,0,"007")
</script>
</body>
</html>点击 "运行实例" 按钮查看在线实例
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>foreach</title>
</head>
<body>
<ul>
<li>01</li>
<li>02</li>
<li>03</li>
<li>04</li>
<li>05</li>
<li>06</li>
<li>07</li>
<li>08</li>
</ul>
<script>
var lis = document.getElementsByTagName('li');
var arr = Array.prototype.slice.call(lis);
arr.splice(3)
</script>
</body>
</html>点击 "运行实例" 按钮查看在线实例
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>foreach</title>
</head>
<body>
<ul>
<li>01</li>
<li>02</li>
<li>03</li>
<li>04</li>
<li>05</li>
<li>06</li>
<li>07</li>
<li>08</li>
</ul>
<script>
var lis = document.getElementsByTagName('li');
var arr = Array.prototype.slice.call(lis);
arr.splice(2,1,"007")
</script>
</body>
</html>点击 "运行实例" 按钮查看在线实例
Copyright 2014-2025 https://www.php.cn/ All Rights Reserved | php.cn | 湘ICP备2023035733号