Crowdly

What type of elements can trigger focus events?

Input elements

100%

Form elements

100%

Button elements

100%

Is there everything ok with the useData hook?

where useUserId is also a custom hook:

Error: Invalid hook call... - because we cannot call custom hooks from custom hooks

Error: Invalid hook call... - because you can only call hooks at the top level

The code is ok

Infinite loop

Please, choose the correct statements about state and effects with using hooks

two components using the same Hook share state and effects

every time you use a custom Hook, all state is fully isolated, but effects are not

every time you use a custom Hook, all state and effects inside of it are fully isolated

Please, select what is true about custom React hooks:

There are no requirements regarding its name

It has to return jsx

There are no requirements regarding its arguments

It doesn't need to return anything

Its name should always start with use

Suppose, we have the next code:

What will happen if ComponentA updates value by calling setValue?

value will be updated, ComponentA will not be rerendered

value will not be updated, ComponentA will not be rerendered

value will be updated, ComponentA will be rerendered

error

Infinite loop

value will not be updated, ComponentA will be rerendered

Please, choose what places error boundaries catch errors in:

render

event handlers

asynchronous code

errors thrown in the error boundary itself

lifecycle methods

Please, choose what happens if error is not caught by any error boundary

unmounting of the whole React component tree

rendering of corrupted UI. No unmounting happens

unmounting the faulty part of React component tree

Please, select what type of component can be an error boundary in React:

only class component

can be class or functional component

only functional component

Will the ErrorBoundary component handle the error in the code below?

No, because error boundary component can handle only issues of children components wrapped with this error boundary component

It will work as if the whole SimpleComponent was wrapped inside of ErrorBoundary

Error that happens in the js does not affect rendering of SimpleComponent. ErrorBoundary is not needed here

Yes, it will handle the jsx inside of it