React assessment on Linkedin

Linkedin offers an online quiz to test React.js skills. I collected questions from this test.

1) When do you use useLayoutEffect?

( ) to change the layout of the screen

( ) when you need the browser to paint before the effect runs

(*) to complete the update

( ) to optimize for all devices

2) How do you fix the syntax error that results from running the code?

const person = (firstName, lastName) => 

{

first: firstName,

last: lastName

} 

console.log(person("Jill", "Wilson"));

( ) Add a return statement before the first curly brace

(*) Wrap the object in parentheses

( ) Call the function from another file

( ) Replace the object with an array

3) What is the children prop?

( ) a property that lets you pass data to child elements

(*) a property that lets you pass components as data to other components

( ) a property that lets you set an array as a property

( ) a property that adds child components to state

4) What is [e.target.id] called in the following code snippet?

handleChange(e) {

this.setState({[e.target.id]: e.target.value})

}

( ) a set value

(*) a computed property name

( ) a dynamic key

( ) a JSX code string

5) What is the name of the tool used to take JSX and turn it into createElement calls?

( ) JSX Editor

( ) Browser Buddy

(*) Babel

( ) ReactDOM

6) Why is it a good idea to pass a function to setStateinstead of an object?

( ) It makes sure that the object is not mutated

( ) It is more functional than an object

(*) setState is asynchronous and might result in out of sync values.

( ) It automatically updates a component

7) When using webpack, why would you need to use a loader?

( ) to put together physical file folders

( ) to load external data

( ) to load the website into everyone's phone

(*) to process files

8) Which of these terms commonly describes React applications?

( ) closed

( ) integrated

(*) declarative

( ) imperative

9) All React components must act like ____ with respect to their props.

(*) pure functions

( ) higher-order functions

( ) recursive functions

( ) monads

10) What do you call the message wrapped in curly braces below?

const message = "Hi there";

const element = <p>{message}</p>

(*) a JSX wrapper

( ) a JS function

( ) a JS expression

( ) a JS element

11) What can you use to handle code-splitting?

( ) React.split

( ) React.fallback

( ) React.memo

(*) React.lazy

12) Which of these Hooks could be used to update a documents title?

( ) useEffect(function() {title = name + ' ' + lastname;})

( ) useEffect(() => {title = name + ' ' + lastname;})

(*) useEffect(function updateTitle() {document.title = name + ' ' + lastname;})

( ) useEffect(function updateTitle() {name + ' ' + lastname;})

13) Which attribute do you use to replace innerHTML in the browser DOM?

(*) dangerouslySetInnerHTML

( ) strangeHTML

( ) weirdSetInnerHTML

( ) injectHTML

14) What property do you need to add to the Susense component in order to display a spinner or loading state?

function MyComponent() {

return (

<Suspense>

                 <div><Message/></div>

</Suspense>

        );

}

( ) spinner

(?) fallback

( ) loading

( ) lazy

15) React components are composed to create a user interface. How are components composed?

( ) with webpack

( ) with code splitting

(*) by nesting components

( ) by putting them in the same file