machinecat520
/
zj-Exercise


			
				
					
						
						
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							<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <!-- 
        1、缺点
            *函数执行完后，函数内的局部变量没有释放，占用内存时间会变长
            *容易造成内存泄漏
        2、解决
            *能不用闭包就不用
            *及时释放
     -->
    <script>

        function fn1() {
            var arr = new Array[100000]
            function fn2() {
                console.log(arr.length)
            }
            return fn2
        }
        var f = fn1()
        f()
        f = null    //让内部函数成为垃圾对象-->回收闭包

    </script>
</body>

</html>