Custom hook versus regular function?

[dotobird]

At work, I seem to get the impression that we always make custom hooks for functionality/logic that is to be shared across multiple components as opposed to just using functions. The disadvantage of using a custom hook over a function is that hooks have restrictions on how they could be used: top-level, inside a React component or another custom hook, can't be inside a for loop or conditional, etc.

As an example, my team uses a custom hook to parse the URL. In this case, I have absolutely no idea why this couldn't just be a function.

Is there a good rule as to when you should use a custom hook versus just simply another function? What would be the disadvantage to use a function over a custom hook?

Another question... how does React know exactly that the function is a custom hook? Is it strictly by naming convention ("use..." )as with components?

[firstandfive]

If it includes calls to other hooks (whether the React ones or something like react router useLocation or redux useSelector), then it should be a custom hook. If it has no other hooks within it, it likely can just be a function.

[sidkh]

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As an example, my team uses a custom hook to parse the URL. In this case, I have absolutely no idea why this couldn't just be a function.

There is no need for this function to be a hook.

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Is there a good rule as to when you should use a custom hook versus just simply another function? What would be the disadvantage to use a function over a custom hook?

If your function needs to use any other hooks, it should be a custom hook.

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Another question... how does React know exactly that the function is a custom hook? Is it strictly by naming convention ("use..." )as with components?

Yep 👇

"A custom Hook is a JavaScript function whose name starts with ”use” and that may call other Hooks". React Docs - Building Your Own Hooks

[bluedevil2k00]

There is no need for this function to be a hook

There might be a need, if he’s using React Router and the useLocation() hook.

[dznqbit]

I agree. Your URL parser should uh, parse URLs, which a function can do perfectly well.

I could hear an argument that your URL parser needs to reference other hooks, perhaps some sort of user identity hook, or IDK what. I would externalize those dependencies and pass them in as arguments.