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dom_practice.html
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dom_practice.html
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<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Practice</title>
</head>
<body>
<!-- 这里将标签之间空格去掉,因为空格也会算为一个节点 -->
<div id="refA"><ul><li><a href="#"></a></li><li><a href="#"></a></li><li><a href="#" id="refB"></a></li></ul></div>
<div></div>
<div></div>
<script>
var refA = document.getElementById('refA');
// var refB = document.getElementById('refB');
document.body.removeChild(refA);
// #refA不能GC回收,因为存在变量refA对它的引用。将其对#refA引用释放,但还是无法回收#refA。
// refA = null;
// 还存在变量refB对#refB的间接引用(refB引用了#refB,而#refB属于#refA)。将变量refB对#refB的引用释放,#refA就可以被GC回收。
// refB = null;
</script>
</body>
</html>