April 2018
Beginner
536 pages
13h 21m
English
Content preview from Learning TypeScript 2.x - Second Edition
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Type inference and optional static type annotations
The TypeScript language service is great at automatically detecting the type of a variable. However, there are certain cases where it is not able to automatically detect a type.
When the type inference system is not able to identify the type of a variable, it uses a type known as the any type. The any type is a value that represents all the existing types, and as a result, it is too flexible and unable to detect most errors, which is not a problem because TypeScript allows us to explicitly declare the type of a variable using what is known as optional static type annotations.
The optional static type annotations are used as constraints on program entities such as functions, variables, and ...
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