functions as objects in JavaScript

Question

There is an object c.
It has a function c.log(message)

Is it possible to add some variables for using them like c.log.debug = true?

• Dmitry: No, but I have some thoughts about prototypes of functions.
• phant0m: What are your thoughts and what do are you trying to accomplish?
• Dmitry: Just a simple console.log wrapper with options (silent mode, easy groups). Actually c is $.

Answer 1

Javascript is a full object-orientated language. That means that (削除) almost (削除ここまで) everything is an object - even functions :

var f = function(){};
alert(f instanceof Function);
// but this statement is also true
alert(f instanceof Object);
// so you could add/remove propreties on a function as on any other object : 
f.foo = 'bar';
// and you still can call f, because f is still a function
f();

Answer 2

With little modification it is possible like this:

var o = {f: function() { console.log('f', this.f.prop1) }};
o.f.prop1 = 2;
o.f(); // f 2
o.f.prop1; // 2

• phant0m: This will break as soon as o.f is passed as a parameter(stored as variable etc...)
• marekful: Yeah, but it's not. It's accessed from within a function that is a property of an object and the function itself has a property too.
• phant0m: I'm not critisizing, just pointing out what to be aware of ;)
• marekful: Ok, I agree this isn't a good approach, shouldn't be used in robust code. But it still allows to use a condition in that function depending on the value of o.f.prop1 which is a read/write property even from outside of o. So it is flexible and may be useful.

Answer 3

It won't work like this. You could instead add the 'debug' flag as a parameter to your function, e.g.

c.log = function(message, debug) {
 if debug {
 // do debug stuff
 }
 else {
 // do other stuff
 }
}

• phant0m: Uhm, depending on what exactly the OP is trying to do, the answer is either yes, or no.
• Dmitry: It's not a solution :) I think the better way will be c.log() + c.logProperties, but it's also not a solution.