Book Image

Professional JavaScript

By : Hugo Di Francesco, Siyuan Gao, Vinicius Isola, Philip Kirkbride
Book Image

Professional JavaScript

By: Hugo Di Francesco, Siyuan Gao, Vinicius Isola, Philip Kirkbride

Overview of this book

In depth knowledge of JavaScript makes it easier to learn a variety of other frameworks, including React, Angular, and related tools and libraries. This book is designed to help you cover the core JavaScript concepts you need to build modern applications. You'll start by learning how to represent an HTML document in the Document Object Model (DOM). Then, you'll combine your knowledge of the DOM and Node.js to create a web scraper for practical situations. As you read through further lessons, you'll create a Node.js-based RESTful API using the Express library for Node.js. You'll also understand how modular designs can be used for better reusability and collaboration with multiple developers on a single project. Later lessons will guide you through building unit tests, which ensure that the core functionality of your program is not affected over time. The book will also demonstrate how constructors, async/await, and events can load your applications quickly and efficiently. Finally, you'll gain useful insights into functional programming concepts such as immutability, pure functions, and higher-order functions. By the end of this book, you'll have the skills you need to tackle any real-world JavaScript development problem using a modern JavaScript approach, both for the client and server sides.
Table of Contents (12 chapters)

Math, Date, and String

When building complex applications using JavaScript, there will be times when you need to deal with string manipulation, math calculations, and dates. Luckily, JavaScript has several built-in methods for this type of data. In the following exercises, we will go over the ways we can utilize these in our applications.

To create a new Date object, use the following command:

const currentDate = new Date();

This will point to the current date.

To create a new string, use the following command:

const myString = 'this is a string';

To use the Math module, we can use the Math class:

const random = Math.random();

Exercise 56: Using String Methods

In this exercise, we will go over some of the ways we can work with strings more easily in our applications. String manipulation and building have always been complex tasks in other languages. In JavaScript, by using String methods, we can create, match, and manipulate strings with ease. In...