这是根据之前的 state 更新 state 的正确方法吗？

Question

Here's my code:

  const [val, setVal] = useState(0);

  function onClick() {
    setVal(val + 1);
  }

I just wanted to check if this is the correct way to update a state based on a previous state? Why/why not?

Answer 1

This is a perfectly fine approach. Note that you could also get the value of your current state as a callback parameter on setVal , eg: setVal(prevState => prevState + 1) .

Just be careful when manipulating arrays or objects since they shouldn't be directly mutated (with methods such as push or pop etc).