Uniqueness of the REACT array key

1. Do not use the index index of the array as key

2, in the adjacent elements, it is necessary to ensure the uniqueness of key, if the same key appears, will throw a Warning, tell the adjacent components have a duplicate key value. And only the elements in the first duplicate key value will be rendered, because react will assume that subsequent ownership of the same key is the same component.

3, stability is important here, because if the key value has changed, react will trigger the UI re-rendering. This is a very useful feature

https://www.jianshu.com/p/c74624223986

Uniqueness of the REACT array key