All language subtitles for 008 Rules of Hooks_en

So we spend a lot of time on you state, but it is the most important state react, offers, react,

offers more hooks than just use state, but it really is an important hook.

If we analyze it, then it's clear that the idea behind you state is that we can manage state in a functional

component by calling you state with some initial state which we can set up.

You don't have to pass an initial state.

By the way, if you want to have null or undefined as initial state, you simply pass no argument at

all to use state.

And this creates a state which is managed by Riak behind the scenes and which survives referendum cycles

and what you get backed by your state is that array with exactly two elements a pointer at your state.

That's the first element and a state update function.

That's the second element.

This is how you state works.

Now, there are two important rules when you work with Hooke's, with any Hooke's, not just with use

state, but also with any other rehook you'll learn about in this module.

For one, you must only use the hooks in functional components or inside of Abre custom hooks, which

will build later.

The second important rule is that you always have to use the hooks on the root level in your component.

Now, what does this mean?

It means that you can't use a hook in the nested function.

Here I have to submit Handler, which isn't doing much right now, but we can't use use state in here,

for example.

And actually we already get an error here because modern reac projects already have code checks which

determined that this year is using a hook in something that's never a react function component nor another

hook, and therefore it's not allowed to use it here.

You're also not allowed to, for example, use a hook in some if statement.

So if you had some condition and then you want to create some state that's also not allowed here.

Unfortunately, my project doesn't determine that this is wrong, but this is simply not allowed.

You must not use your hooks in a for loop.

And if statement or in another function, use it on the root level of your functional component or on

the root level of approx.