Comments on: Array-like Objects in JavaScript

By: mister

mister — Thu, 11 Dec 2008 12:31:14 +0000

But what doesn’t work is sending a resonse!
The half of my response above is missing!!

By: mister

mister — Thu, 11 Dec 2008 12:27:50 +0000

You can also find out that $A returns an Array by checking with:

var arr = $A(1,2,3);
if ( !(arr instanceof Array) )
document.write(“!!!shit!!!”);

There is no !!!shit!!! it works!

By: Pops

Pops — Thu, 06 Sep 2007 23:08:32 +0000

Dude! You are a freaking LIFE SAVER! I’m a veteran C/C++ guy dealing with pointers all the freaking time, and I was trying desperating to fiqure out how to pass the poitner to the arguments[1] after my function analyzed the optional first object parameter.

I spent hours tryiing to do this, trying to shift directly, shifting a copy, trying to pass a c-like &arguments[1]… NOPE!!

Your prototype solution hurts because I NEED TO KNOW JAVASCRIPT BETTER!

My final solution is

function log(prefix, argv)
{
if (typeof(prefix) != “string”) {
var args = Array.prototype.slice.call(arguments); // EUREKA!
logArgs(args,prefix);
} else {
logArgs(arguments,”");
}
}

Thanks a million. I had to write to tell ya YOU helped mankind!

By: K. Adam Christensen

K. Adam Christensen — Fri, 29 Jun 2007 14:27:48 +0000

D’oh. Yeah, @var $A = Array.prototype.slice.call@ won’t work at all. What was I thinking!?!? Good catch!

Array isn’t a primitive data type as you noticed that @typeof []@ will return @object@; however, if you do @[].constructor@, you will see that it is an Array.

By: Tore Darell

Tore Darell — Fri, 29 Jun 2007 08:24:42 +0000

Nifty. I'm a bit surprised that slice works like that. That last bit doesn't work for me unless I do

var $A = function(){ return Array.prototype.slice.call(arguments); }

And even the "real" array returned by this won't actually be an array in the traditional sense.. Arrays in JS are basically just hash maps (objects) that use integers as keys and behave like arrays.. Thus, if you do typeof [] you get 'object' back. Quirky, indeed. arguments not being an array can be annoying though.