Practice

Question 1ReactBeginnerChoose one answer

What is React primarily used for?

This checks the core definition of React.

Separate React itself from the tools a complete application may add.

Your answer

Building user interfaces from components.Managing relational databases.Replacing JavaScript in the browser.Writing CSS without stylesheets.

Topics:reacttheoryfundamentals2 min · FrontCrate Editorial · Updated 2026-08-12 · React: Quick Start

Question 2ReactBeginnerChoose one answer

True or false: React itself prescribes routing, data fetching, and a backend for every application.

React focuses on the UI component model; applications choose the rest of their stack.

Identify which concerns React handles directly.

Your answer

TrueFalse

Topics:reacttheorytrue-false2 min · FrontCrate Editorial · Updated 2026-08-12 · MDN: Getting started with React

Question 3ReactBeginnerChoose all that apply

Which are benefits of building an interface with React components?

Select every answer that describes a component-based benefit.

There are three correct answers.

Your answer

Reusable UI patterns can be defined once and composed in multiple places.A component can receive data through props.React removes the need to understand JavaScript.The UI can be described as a function of current data and state.

Topics:reactcomponentstheory2 min · FrontCrate Editorial · Updated 2026-08-12 · React: Quick Start

Question 4ReactBeginnerChoose one answer

Which JSX line correctly gives a div the CSS class card?

JSX resembles HTML, but some attribute names follow JavaScript conventions.

// Choose the valid JSX line

In JSX, class is not the attribute name.

Your answer

Topics:jsxcode-readingattributes2 min · FrontCrate Editorial · Updated 2026-08-12 · React: Writing markup with JSX

Question 5ReactBeginnerChoose all that apply

Which JSX expressions render the user name correctly?

Select every valid way to include a JavaScript value in JSX.

const user = { name: "Ada", imageUrl: "/ada.png" };

There are two correct answers.

Your answer

Topics:jsxcode-readingexpressions2 min · FrontCrate Editorial · Updated 2026-08-12 · React: JavaScript in JSX with curly braces

Question 6ReactBeginnerChoose one answer

What does this component composition render?

Read the component tree and identify the resulting UI.

function Button() { return <button>Save</button>; }

export default function Toolbar() {
  return <section><h1>Editor</h1><Button /></section>;
}

Capitalized JSX tags refer to React components.

Your answer

A section containing an Editor heading and a Save button.Only the Save button, because Button replaces Toolbar.A syntax error because components cannot be nested.A section containing the literal text <Button />.

Topics:reactcomponentscode-reading2 min · FrontCrate Editorial · Updated 2026-08-12 · React: Your first component

Frontend MCQs

Frontend MCQs