垃圾收集：对象属性 [英] Garbage collection: object properties

问题描述

假设我有一个对象包含其他对象作为其属性，如

Let's say I have an object that contains another objects as its properties like

var obj = {
    '1': {...},
    '42': {...}
};

当 obj 超出范围时 - 做所有嵌套对象都是隐式销毁的，或者我需要迭代它们并且删除显式？

When obj gets out of scope - do all nested objects destroyed implicitly or I need to iterate over them and delete explicitly?

推荐答案

是的，除非另一个参考仍然存在：

Yes, unless another reference still exists :

var obj = {
    '1': {...},
    '42': {...}
};


var save = obj['1'];

obj = null; 

垃圾收集后，假设没有创建其他引用，那么obj和obj的空间['42 ']将被恢复，保存的值当然会被保留。

After garbage collection and assuming no other references have been created then the space for obj and obj['42'] would be recovered, the value of saved would of course be preserved.

Mea culpa：如评论中所述 delete obj 无效，因为 obj 被声明为 var 。如果 obj 是一个全局对象，因此是全局对象的属性， delete 就可以了。要有效删除var，请使用 obj = null 。
我学会测试的一件事是删除一个运算符并返回 true 或假。

Mea culpa : as mentioned in the comments delete obj in my original is not valid since obj was declared as a var. Had obj been a global and hence a property of the global object, delete would have worked fine. To effectivly delete a var, use obj = null. One thing I learned testing this was that delete an operator and returns true or false.

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