Book Image

JavaScript from Beginner to Professional

By : Laurence Lars Svekis, Maaike van Putten, Codestars By Rob Percival
4 (5)
Book Image

JavaScript from Beginner to Professional

4 (5)
By: Laurence Lars Svekis, Maaike van Putten, Codestars By Rob Percival

Overview of this book

This book demonstrates the capabilities of JavaScript for web application development by combining theoretical learning with code exercises and fun projects that you can challenge yourself with. The guiding principle of the book is to show how straightforward JavaScript techniques can be used to make web apps ranging from dynamic websites to simple browser-based games. JavaScript from Beginner to Professional focuses on key programming concepts and Document Object Model manipulations that are used to solve common problems in professional web applications. These include data validation, manipulating the appearance of web pages, working with asynchronous and concurrent code. The book uses project-based learning to provide context for the theoretical components in a series of code examples that can be used as modules of an application, such as input validators, games, and simple animations. This will be supplemented with a brief crash course on HTML and CSS to illustrate how JavaScript components fit into a complete web application. As you learn the concepts, you can try them in your own editor or browser console to get a solid understanding of how they work and what they do. By the end of this JavaScript book, you will feel confident writing core JavaScript code and be equipped to progress to more advanced libraries, frameworks, and environments such as React, Angular, and Node.js.
Table of Contents (19 chapters)
16
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17
Index

Summary

In this chapter, we have covered functions. Functions are a great JavaScript building block that we can use to reuse lines of code. We can give our functions parameters, so that we can change the code depending on the arguments a function gets invoked with. Functions can return a result; we do so using the return keyword. And we can use return at the place where we call a function. We can store the result in a variable or use it in another function, for example.

We then met with variable scopes. The scope entails the places from where variables are accessible. Default let and const variables can be accessed inside the block where they're defined (and the inner blocks of that block) and var is just accessible from the line where it was defined.

We can also use recursive functions to elegantly solve problems that can be solved recursively by nature, such as calculating the factorial. Nested functions were the next topic we studied. They are not a big deal,...