Javascript Absolute Beginner's Guide, 3rd Edition

8

Variable Scope

In this Chapter

• Understand global scope

• Familiarize yourself with the various techniques available for using local scope

• Learn about some quirks that might cause your code to behave unpredictably

Let’s revisit something relating to variables we saw a few chapters ago. Each variable we declare has a certain level of visibility that determines when we can actually use it. In human-understandable terms, just because we declare a variable doesn’t mean that it can be accessed from anywhere in our code. There are some basic things we need to understand, and this whole area of understanding falls under a topic known as variable scope.

In this chapter, I’m going to be explaining variable scope by looking at common cases that we’ve ...