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Javascript 基础之 Map 和 WeakMap #4

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Ziphwy opened this issue Nov 3, 2020 · 0 comments

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Javascript 面试基础

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Ziphwy commented Nov 3, 2020

总结：

Map 是有序键值对集合，Map 内部使用数组实现，读写时需要 O(n) 时间遍历 key 数组
WeakMap 是解决 Map 使用 Object 作为 key 形成强引用，无其他引用也无法被 GC 的问题，因此只允许 Object 作为 key
WeakMap 对 key 是弱引用，Object 在没有其他引用时就能被 GC
受 GC 的影响，WeakMap 无法返回确定性的 key，设计上不可枚举

MDN WeakMap 解释

Ziphwy added Javascript 面试基础 labels

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