December 2019
Beginner
464 pages
10h 31m
English
Content preview from JavaScript Absolute Beginner's Guide, 2nd Edition
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22. Null and Undefined
In This Chapter
• Learn about when values don’t exist
• Understand what to do with null and undefined
One of the great mysteries of the world revolves around making sense of null and undefined. Most code you see is littered with them, and you’ve probably run into them yourself a few times. As mysteries go, making sense of null and undefined isn’t particularly bizarre. It is just dreadfully boring...like the most boring (yet important) thing about JavaScript you’ll ever have to learn.
Onward!
Null
Let’s start with null. The null keyword is a primitive that fills a special role in the world of JavaScript. It is an explicit definition that stands for no value. If you’ve ever browsed through code others have written, ...
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