Cast function parameter type in Typescript

Question

Forcibly change a functions parameter type by casting itself.

It looked like

(<number>foo)(1)

Where

function foo( v : string )

Answer 1

You can't change the function param types but you can cast (type assert) the param you're passing to it to any:

function fn(obj: string) {
    ...
}

fn(1 as any);

But you can make the function more generic:

function fn(obj: string | number) {
    ...
}

fn(1);
fn("str");

You can also use generics:

function fn<T>(obj: T) {
    ...
}

fn(1);
fn("str");