December 2016
Intermediate to advanced
841 pages
17h
English
Content preview from TypeScript: Modern JavaScript DevelopmentBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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Chapter 6. Advanced Programming in TypeScript
In the previous chapters, we learned the basics of TypeScript and we worked with various frameworks. We will discover more advanced features of TypeScript in this chapter. This chapter covers the following aspects:
- Using type guards
- More accurate type guards
- Checking null and undefined
- Creating tagged union types
- Comparing performance of algorithms
Using type guards
Sometimes, you must check whether a value is of a certain type. For instance, if you have a value of a class Base, you might want to check if it is of a certain subclass Derived. In JavaScript you would write this with an instanceof check. Since TypeScript is an extension of JavaScript, you can also use instanceof in TypeScript. In other typed ...
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.