Question

I am building functions to help with urls:

var ap = { /* lots of things removed */ }

ap.url = function(base) {
    this.base  = base
    this.data  = "cb_=" + parseInt(Math.random()*99999999);
}

ap.url.prototype = {
    nv: function (n,v) {this.data=this.data+"&"+ n+"="+encodeURIComponent(v)},
    get: function () { return this.base + "?" + this.data; }
};


var u = new ap.url("site.com");
u.nv("p1", "123");
u.nv("p2", "456");

alert( u.get() )

And this appears to work ok.

Is it possible to create a prototype for the object itself? Like:

alert( u() )

I would like u() to do the same thing as u.get()

Answer 1

No, because “u” is not a Function instance. You can however give your “ap.url” prototype a “toString()” and/or “valueOf()” functions to provide string and number representations. Those are used implicitly in various circumstances. Then you can (for example) use a reference to one of those objects in a string concatenation expression, and the runtime will implicitly call your “toString” function.

function C(v) {
  this.internal = v;
}

C.prototype = {
  toString: function() { return this.internal; }
};

var c = new C("hello world");

alert("The value is: " + c);