ES6 Promises, Classes, and Modules

Question 1

What are the three states a Promise can be in?

Answer 1

Pending:
Initial state, neither fulfilled nor rejected

Fulfilled:
Meaning that the operation was completed successfully

Rejected:
Meaning that the operation failed

Question 2

How do you handle the fulfillment of a Promise?

Answer 2

You call the then method of the promise object with a callback function

Question 3

How do you handle the rejection of a Promise?

Answer 3

You call the catch method of the promise object with a callback function

Question 4

What is “syntactic sugar”?

Answer 4

Syntax within a programming language that is designed to make things easier to read or to express

Question 5

What is the typeof an ES6 class?

Answer 5

A Function

Question 6

Describe ES6 class syntax.

Answer 6

class Person {
	constructor(name) {
		this.name = name;
	}
	function() {
		function code
	}
}

Question 7

What is “refactoring”?

Answer 7

Refactoring is re-writing code for readability and useability with abstraction while not changing the behavior

Question 8

How are ES6 Modules different from CommonJS modules?

Answer 8

ES6 Modules are pre-parsed in order to resolve further imports before code is executed.

CommonJS modules load dependencies on demand while executing the code.

const varName = require(‘./file-path’); → 
import class/functionName from ‘./file-path’;

Question 9

What kind of modules can Webpack support?

Answer 9

ES6, CommonJS, and AMD Modules