javascript - Function call with additional sub functions -

i'm asking myself if it's possible call function in js, while having additional subfunction inside it

fn(s);  fn.subfn(s);

for example make utils this

var s = "123"; string(s) // true string.blank(s) // false

i think it's possible this:

function string(s) {   if(s) return typeof(s) === "string";   return {     blank: function(s) {       return s.trim().length === 0;     }   } }

but every time call string(s) i'm redefining blank fn, possible poor performances , poor code, or i'm wrong?

thanks.

functions objects, yes, can add properties them:

function string(s) {   return typeof(s) === "string"; }  string.blank = function(s) {     return s.trim().length === 0; }

this allow make calls

string(s); string.blank(s);

just shown in example.

comments code:

the function defined returns object when call string, require call function

string().blank(s);

which different form example showed @ beginning.

LAVA