Possible conceptual pitfall when discussing accessing a state variable set in a previous render

Hi there!

In this section: https://react.dev/learn/you-might-not-need-an-effect#adjusting-some-state-when-a-prop-changes

It took me a while to understood that prevItems would not be changed until setItems was invoked on it. What tripped me there was that I thought that useState(X) always set items to X on every re-render. Once I understood that prevItems is set to X only when the state is initialized, everything is clear.

This might perhaps be a good place in the docs to clarify (either on a couple of sentences or on its own Pitfall section) that setState will only initialize a value, but not update it during a re-render.

I take this opportunity for congratulating the team on the new React docs. There are one of the best technical documentation pieces I've read in my entire career. 🚀

閱讀 React 文件中連結的「Adjusting some state when a prop changes」章節，並檢查其中對跨次 render 的 useState 和 setState 的說明。完成標準是該章節清楚區分 state 的初始初始化與後續更新，並處理所回報的誤解。