Typescript conversion to boolean

Question

In Typescript I can do this:

var xxx : some_type;  if (xxx)     foo(); else     bar(); 

Here xxx will be treated as a boolean, regardless of its type.

I would like to do the same thing in a function argument. I have this function:

function foo(b : boolean) { ... } 

I want to be able to call foo(xxx) and have xxx treated as a boolean, regardless of its type. But Typescript won't allow that.

I tried this:

foo(<boolean>xxx); 

but that Typescript won't allow that either.

I can do this:

foo(xxx ? true : false); 

But that seems a bit silly. Is there a better way to do it?

Answer 1

You can use double exclamation sign trick which Typescript does allow and which works fine in JavaScript:

foo(!!xxx); 

Alternatively, cast it to any

foo(<any>xxx);