Custom Type Guards
Explore how to define custom type guards in TypeScript that return boolean values and refine types within conditional control flows. Learn to implement runtime checks to validate data from external sources safely. Understand the balance between type assertions and actual runtime validation to reduce errors caused by incorrect type assumptions.
We'll cover the following...
We'll cover the following...
Overview
TypeScript lets you define your own type guards. A custom type guard is a Boolean-returning function that can additionally assert something about the type of its parameter. If the function is called in the context of a conditional expression, the type of the passed value is narrowed to the asserted type inside the ...