React

Question 1

What is Webpack?

Answer 1

A bundler for your JavaScript files, their dependencies and other assets of your application (ex CSS, images, html)

Question 2

How do you add a devDependency to a package?

Answer 2

npm install –save-dev

Question 3

What is an NPM script?

Answer 3

CLI commands you can add to the scripts section/property of package.json. You can give the commands a name and run them using
npm run

Question 4

How do you execute Webpack with npm run?

Answer 4

Depends on what name you give the npm script

Usually it’s npm run build

Question 5

How are ES Modules different from CommonJS modules?

Answer 5

ES modules are used on the front-end when working with javascript running on the browser;

Common js modules and require statements and module.exports are used with Node on the backend

Question 6

What kind of modules can Webpack support?

Answer 6

Most of them??

Webpack supports the following module types natively:

ECMAScript modules
CommonJS modules
AMD modules
Assets
WebAssembly modules

Question 7

What is React?

Answer 7

Javascript library for creating user interfaces;

Question 8

What is a React element?

Answer 8

jsx that describes a piece of UI

Question 9

How do you mount a React element to the DOM?

Answer 9

ReactDOM.render() method

Question 10

What is a React component?

Answer 10

A JavaScript function or class that accepts inputs called props and returns a react element

Question 11

How do you define a function component in React?

Answer 11

function ComponentName(props) {
  return < html >Hello, {props.name}< html >;
}

Question 12

What are props in React?

Answer 12

Arguments/inputs to a react component, they are accessed as properties on an object called props

Question 13

How do you pass props to a component?

Answer 13

Through the component’s attributes

Question 14

How do you write JavaScript expressions in JSX?

Answer 14

Enclosed in {}

Question 15

How do you create “class” component in React?

Answer 15

extend the React.Component base class; give it a render function that returns jsx

Question 16

How do you access props in a class component?

Answer 16

this.props - meaning props is an instance property on the class, state is as well

Question 17

What is the purpose of state in React?

Answer 17

to encapsulate data locally to component

”State is similar to props, but it is private and fully controlled by the component.”

Question 18

How do you pass an event handler to a React element?

Answer 18

Use use the function’s bind method to set its this value, then pass as an attribute like any other prop

or wrap event handler call arrow function