javascript - 对于 WeakMap， "circular"引用会被视为 "reachability"吗？

Question

function f() {
  const w = new WeakMap();
  const o = {};

  w.set(o, { v: o });

  return w;
}

const weakMap = f();

对于给定的代码，唯一的 weakMap 项目是否被认为是可达的？因此，它是否会被垃圾收集？

PS:这个问题是从规范的 Angular 问的，不是具体的实现。

Answer 1

引用 WeakMap Objects section ,

If an object that is being used as the key of a WeakMap key/value pair is only reachable by following a chain of references that start within that WeakMap, then that key/value pair is inaccessible and is automatically removed from the WeakMap.

在您的情况下，到达 o 的唯一方法是从 weakMap 中的一个键开始，因为没有对其的外部引用。因此，它将被视为不可访问。

WeakMap implementations must detect and remove such key/value pairs and any associated resources.

因此，它最终会被垃圾回收。