Explicit type annotation vs "as" keyword [duplicate]

Question

const names: string[] = [];
const names = [] as string[];

In TypeScript, is there a semantic difference between the above two statements? If so, when would we prefer one over the other?

Answer 1

It's simple as:

• Use type annotation if you want a new variable to be of that type.
• Use type assertion (as keyword) if you want to tell the compiler that some expression has some specific type (even if it doesn't really).