TypeScript tutorialLesson 13Free preview

TS Functions

This lesson is part of TypeScript · All levels

Summary

The TypeScript function can be annotated for parameters or return values, so the calling error is caught early. The parameters support question marks for optional and rest parameters for dynamic number arguments. This annotation makes the function as well as the living documentation of how to use it.

Key points

Annotation of parameters and types increases security
Optional parameters using the question mark
The rest parameter collects the argument into an array

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