What are advanced type guards in TypeScript?

What are advanced type guards in TypeScript?

Advanced type guards in TypeScript allow you to create more complex type checks using user-defined type predicates and conditional types.

Can you give me an example of a user-defined type guard?

Sure! Here's an example:

function isString(value: any): value is string {
    return typeof value === 'string';
}

This function checks if a value is a string and narrows the type accordingly.

How do conditional types work with type guards?

Conditional types allow you to create types based on conditions. For instance:

type IsString<T> = T extends string ? 'Yes' : 'No';

This type will evaluate to 'Yes' if T is a string, otherwise 'No'.

What are some common use cases for advanced type guards?

Common use cases include validating API responses, creating utility functions for type narrowing, and enhancing type safety in complex applications.