React Native Practice Test

Question 1

What is the meaning of Babel?

Accepted Answer

A JavaScript Compiler

Answer

Babel is primarily known as a JavaScript compiler. Its main function is to transform modern JavaScript code (like ES6+) into a backwards-compatible version of JavaScript that can be run by older browsers or environments. While it often acts as a transpiler (source-to-source compiler), its broader role is to compile newer syntax into widely supported JavaScript.

Question 2

What is the implementation of the Navigator component in React Native?

Accepted Answer

JavaScript

Answer

The Navigator component, or navigation solutions in general within React Native, are implemented using JavaScript. React Native itself allows you to build native mobile apps using JavaScript and React. All components, including those for navigation, are written and managed within the JavaScript environment, which then bridges to native UI components.

Question 3

Who was the author of the JSL when it was first written?

Accepted Answer

Jordan Walke

Answer

Jordan Walke, a software engineer at Facebook, is credited with creating React (and subsequently React Native). He developed the initial prototype of React, which was later open-sourced and became widely adopted for building user interfaces. His work laid the foundation for the declarative component-based approach that defines React and React Native.

Question 4

What is the method for passing data to a component from the outside in React?

Accepted Answer

props

Answer

In React and React Native, 'props' (short for properties) is the mechanism used to pass data from a parent component to a child component. Props are read-only and allow components to receive configuration and data from their parent. This is the fundamental way to communicate data down the component tree, enabling dynamic and reusable component structures.

Question 5

Which HTML keywords aren't available in JSX?

Accepted Answer

both a & b

Answer

JSX is a syntax extension for JavaScript that allows you to write HTML-like code within your JavaScript files. However, because JSX is still JavaScript, it cannot use reserved JavaScript keywords directly. 'for' is a JavaScript loop keyword, and 'class' is a JavaScript keyword for defining classes, so in JSX, you use `htmlFor` and `className` respectively to avoid conflicts.