Java添加删除集的方法 [英] Java add remove methods of sets

问题描述

为什么方法add(<T> element)和remove(Object o)接受不同的参数?

Why does the method add(<T> element) and remove(Object o) accept different arguments?

例如，在Set<Short>中添加短元素.为什么方法remove接受Object?如果您无法添加任何其他数据类型，为什么还要删除其他数据类型?

For example in a Set<Short> you add short elements. Why does the method remove accepts Object? If you can't add any other data type, why would you remove other data type?

谢谢.

推荐答案

add(<T> element):确保仅添加一个T元素.

add(<T> element) : to ensure that just a T element is added.

remove(Object o):即使T元素是对象引用的引用，您也可以删除它.

remove(Object o) : you can delete the T element even if it's a referenced by an Object reference.

例如:

T t = new T();
Set<Short> set = new HashSet<Short>();
Short number = 2;
set.add(number);
Object numberObject = number;
set.remove(numberObject) // it will remove 2 from the set.

为什么要删除其他数据类型?我们不会删除其他数据类型，但是即使对象引用(如示例中)引用了数据，我们也可以删除数据.

why would you remove other data type? we're not removing another data type, but we can remove data even if it is referenced by an Object reference (like in the example).

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