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Why do Hooks rely on call order?
The actual Hooks proposal solves this by relying on the call order: even if two Hooks use a name state variable, they would be isolated from each other. Every useState() call gets its own “memory cell”. There are still a few other ways we could work around this flaw but they also have their own issues.
What is a hook call?
Code that handles such intercepted function calls, events or messages is called a hook. Examples might include intercepting keyboard or mouse event messages before they reach an application, or intercepting operating system calls in order to monitor behavior or modify the function of an application or other component.
Does order of useEffect matter?
useEffect order Everything outside the effects will run first, and then the effects will be called in order. Notice that useEffect accepts a dependency array, which will trigger the effect when the component first mounts and when any of the dependencies change.
Why does react depend on the Order of hooks?
The answer is that React relies on the order in which Hooks are called. Our example works because the order of the Hook calls is the same on every render: As long as the order of the Hook calls is the same between renders, React can associate some local state with each of them.
When do I use functions in a hooks dependency array?
The linter will now ask us to add uid to the dependency array because uid is apart of the side effect. “But uid isn’t state, it’s props!” That’s okay, even though it’s not our component’s state it’s state somewhere else (like in our parent) so it’s the same idea.
Is it OK to call other hooks in react?
If you break these rules, you might see this error. You can use the eslint-plugin-react-hooks plugin to catch some of these mistakes. Custom Hooks may call other Hooks (that’s their whole purpose). This works because custom Hooks are also supposed to only be called while a function component is rendering.
When to use a hook in a JavaScript function?
Hooks are JavaScript functions, but you need to follow two rules when using them. We provide a linter plugin to enforce these rules automatically: Don’t call Hooks inside loops, conditions, or nested functions. Instead, always use Hooks at the top level of your React function.