Immediately Invoked Function Expressions
Explore how immediately invoked function expressions (IIFEs) create local scopes to prevent variable conflicts and global scope pollution in JavaScript. Understand their syntax, variations, and practical use cases including solving common closure interview questions involving loops and setTimeout.
We'll cover the following...
Introduction
One of the goals of functional programming is to reign in the scope of variables. We want variables to only be accessible in their small, local scope, and only where they’re needed. This reduces the chance of bugs, since we can quickly find all pieces of code that a variable is connected to.
This lesson discusses one way to implement this idea. We’re learning a tool to reign in variable scope and keep variables as localized as possible.
Scope Pollution
Writing code often pollutes the global scope. Depending on what we’re doing, we can have dozens of variables in our file and it’s easy to lose track of them.
Eventually, when our code gets complex, we’ll start running into errors where we’ve named variables the same thing. ...