undefined

[ghost]

can you support undefined constant for function argument?
when I use

function($foo=null){}

you convert it to

function(foo){
    if(typeof foo=== "undefined"){
        foo=null;
    }
}

can you do this?

define('undefined'=null);//defined somewhere

function($foo=undefined){}

convert to

function(foo){}

just for optimalization. sometime I use some like this in js

function testFoo(foo){
    if(typeof foo=== "undefined"){ // this not need be here
        foo=null;
    }
    if (!foo){
        //I do some here
    }
}
testFoo();