What does ‘co-variance’ mean for function return types in TypeScript?

Question

TypeScript Associate — Hard

What does ‘co-variance’ mean for function return types in TypeScript?

Accepted Answer

In TypeScript, co-variance for function return types means that a function returning a subtype can be assigned to a variable typed as returning the supertype. This is because return types are covariant, allowing for more flexibility in assigning functions to variables.