November 2019
Beginner
804 pages
20h 1m
English
Content preview from Learn TypeScript 3 by Building Web Applications
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String literal types
A nice alternative to enums and string enums in TypeScript is string literal types. They provide a way to specify the value that a string must have and can actually provide the same kind of behavior as enums. One benefit of string literal types is that you can also combine them with type guards, type aliases, and unions.
The following is an example:
type Mood = "Great" | "Good" | "Bad" | "Awful"; const myCurrentMood: Mood = "Great"; // may only be assigned values that are part of the Mood union!
With the Mood type defined, we can get auto-completion, as shown in the following screenshot:
While using this type, you are, ...
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