Reliable JavaScript: How to Code Safely in the World's Most Dangerous Language

INTRODUCTION

WHEN WE SHARED THE TITLE OF THIS BOOK, Reliable JavaScript, with fellow developers, we received feedback such as:

• “Now there's a juxtaposition!”
• “It must be a very short book.”
• “Will I find it next to the latest John Grisham thriller in the fiction section of the bookstore?”

No, this book is not a work of fiction.

The feedback we received about the title of the book illustrates a broader perception about JavaScript that some developers with experience in classical, compiled languages have: JavaScript is used to create flashy portfolio websites or simple to-do apps; it has no business in my mission-critical enterprise application.

In the past that was true, but no more.

THE RISE OF JAVASCRIPT AS A FIRST-CLASS LANGUAGE

JavaScript's reputation as a wild child is well-deserved, and we hope to amuse you with some of its exploits in the next two sections. However, like a spoiled heiress who inherits the family business and surprises everyone by rising to the challenge, she has turned serious and responsible, lately showing herself capable of true greatness.

Her early life was as a dilettante, rarely entrusted with anything more than short “scripting” tasks. The decisions she made were simple: If a required field was not filled in, she should color it red; if a button was clicked, she should bring another page into view. Although her responsibilities were limited, she was easy to get along with and made many friends. To this day, most programmers' experience of her ...