State Updates are Merged

When you call setState(), React merges the object you provide into the current state.

For example, your state may contain several independent variables:

constructor(props) { super(props); this.state = { posts: [], comments: [] }; }

Then you can update them independently with separate setState() calls:

componentDidMount() { fetchPosts().then(response => { this.setState({ posts: response.posts }); }); fetchComments().then(response => { this.setState({ comments: response.comments }); }); }

The merging is shallow, so this.setState({comments}) leaves this.state.posts intact, but completely replaces this.state.comments.

这个意思是多个state分开更新，会在合并之后然后执行render() 而不是更新一个state render()一次？
这么理解有问题么？