Actually I saw a line of code on router.d.ts, like

isActive(url: string | UrlTree, exact: boolean): boolean;

Then I quickly learn about it and getting some knowledge about Union Types in typescript

So I tried it to implement on my application instead of using Any

Statement 1

function(param: string | number) {    
}

Statement 2

function(param: any) {    
}

I understood my statement 1 is pretty good for limiting data type count from using any (or instead of using any)

But I know typescript is an type safe scripting language. But what about type safe is an possible, if we override datatype's? and share your more knowledge about it.