Book Image

Clean Code in JavaScript

By : James Padolsey
Book Image

Clean Code in JavaScript

By: James Padolsey

Overview of this book

Building robust apps starts with creating clean code. In this book, you’ll explore techniques for doing this by learning everything from the basics of JavaScript through to the practices of clean code. You’ll write functional, intuitive, and maintainable code while also understanding how your code affects the end user and the wider community. The book starts with popular clean-coding principles such as SOLID, and the Law of Demeter (LoD), along with highlighting the enemies of writing clean code such as cargo culting and over-management. You’ll then delve into JavaScript, understanding the more complex aspects of the language. Next, you’ll create meaningful abstractions using design patterns, such as the Class Pattern and the Revealing Module Pattern. You’ll explore real-world challenges such as DOM reconciliation, state management, dependency management, and security, both within browser and server environments. Later, you’ll cover tooling and testing methodologies and the importance of documenting code. Finally, the book will focus on advocacy and good communication for improving code cleanliness within teams or workplaces, along with covering a case study for clean coding. By the end of this book, you’ll be well-versed with JavaScript and have learned how to create clean abstractions, test them, and communicate about them via documentation.
Table of Contents (26 chapters)
1
Section 1: What is Clean Code Anyway?
7
Section 2: JavaScript and Its Bits
13
Section 3: Crafting Abstractions
16
Section 4: Testing and Tooling
20
Section 5: Collaboration and Making Changes

Conversion, coercion, and casting

So far, we have learned how to tell the difference between various types and characteristics within JavaScript using detection. As we have seen, detection is useful when needing to provide alternative values or warnings in the case of unexpected or incompatible values. There is an additional mechanism for dealing with such values, however: we can convert them from the values we don't desire into the values we do desire.

In order to convert a value, we use a mechanism known as casting. Casting is the intentional and explicit derivation of one type from another type. In contrast to casting, there is also coercion. Coercion is the implicit and internal process of conversion employed by JavaScript when we use operators or language constructs that require specific types. An example of this would be when passing String values to a multiplication...