java - 为什么列表的 remove() 方法采用 Object 而不是 T？

Question

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Answer 1

这个问题与现有代码和规范的向后兼容性有关。

What are the reasons why Map.get(Object key) is not (fully) generic

一切都在 Javadoc 的细节中:

boolean remove(Object o)

Removes a single instance of the specified element from this collection, if it is present (optional operation). More formally, removes an element e such that (o==null ? e==null : o.equals(e)), if this collection contains one or more such elements. Returns true if this collection contained the specified element (or equivalently, if this collection changed as a result of the call).

因此您会发现，对象是否具有相同类型并不重要，只要它们相等即可。