I’ve seen a lot of projects that use dispatch as a dependency of useEffect hook in react and I wondered that dispatch is a function and why should I pass it inside useEffect hook?
I guess this is because of our store, I meant it’s a reference to our store.
2
Answers
In many React projects that utilize a state management library like Redux or React Context, the dispatch function is often passed as a dependency to the useEffect hook. This is because the dispatch function is typically used to update the state or trigger actions in the store.
When you include dispatch as a dependency of the useEffect hook, it ensures that the effect will re-run whenever the dispatch function changes. This is important because if the dispatch function changes, it usually means that the state management library has been updated or reconfigured in some way.
By including dispatch as a dependency, you can handle specific side effects or perform certain actions in response to state changes or dispatched actions. This is a common pattern in Redux or React Context-based applications, where you may want to respond to changes in the store’s state or dispatch additional actions based on certain conditions.
However, it’s worth mentioning that including dispatch as a dependency in every useEffect hook might not always be necessary. In some cases, you may only need to include specific state variables or other dependencies that directly affect the behavior of the effect. It’s important to consider the specific requirements of your component and determine which dependencies are truly necessary for your effect to function correctly.
You don’t have to pass dispatch as a dependency. The returned references from hooks are known as ‘closed-over’ or ‘captured’ values, meaning that the ‘hook’ in use maintains the references it returns. In the case of useDispatch, its captured reference must remain the same during the lifetime of the component. One of the triggers for a re-render in useEffect is when the arguments you pass as references change.
With that said, it doesn’t make any difference to your code whether you use it as a dependency or not. Usually, in VSCode, it will give you an error if you don’t use it, but that is an ESLint error, and we comply with it.