JavaScript Patterns: Build Better Applications with Coding and Design Patterns

by Stoyan Stefanov

For example, it’s easier to say (and think) “immediate function,” than “this thing where you wrap the function in parentheses and at the end of it put another set of parentheses to invoke the function right where you’ve defined it.”

Access to the Global Object

Single var Pattern

Hoisting: A Problem with Scattered vars

for Loops

switch Pattern

Avoiding Implied Typecasting

In this chapter we looked at what it means to write maintainable code — a topic that is important not only for the success of a software project but also to the sanity and well-being of the developers and those around them. Then we talked about some of the essential best practices and patterns including: Reducing the number of globals, ideally to one per application Using a single var per function, which helps keep an eye on all variables in a single spot and prevents surprises caused by the variable hoisting behavior for loops, for-in loops, switches, “eval() is evil,” not augmenting built-in prototypes Following coding conventions (consistent white space, indentation, using curly braces and semicolons even when they are optional) and naming conventions (for constructors, functions, and variables) The chapter also discussed some additional practices, not related to the code, but to the programming process in general — writing comments, creating generated API documentation, conducting peer reviews, not attempting to write minified code at the expense of readability, and always checking your code with JSLint.

We’ll talk more about prototypes and inheritance in the chapters to come, but just remember that reusable members, such as methods, should go to the prototype.