Converting the "arguments" object to an array in javascript

Question

As a trivia question, I'm trying to write a javascript function that returns its variable number of arguments in sorted (normal lexicographic) order.

Having never dealt with javascript before, I came across the "arguments" object, which seems to work somewhat like an array but without having the standard array functions -- therefore I seem to need to copy its contents into a "real" array.

Is there a shorter/more concise way of doing this (preferably in a single line)?

function sortArgs() 
{
    args = new Array(); 
    for (var i = 0; i < arguments.length; i++) 
        args[i] = arguments[i]; 
    return args.sort();
}

UPDATE:
Brownie points for explaining how your answer works, since I'm new to JS. I understand slice(), but not the rest of it..

Answer 1

Use:

function sortArgs() 
{
    var args = Array.prototype.slice.call(arguments, 0);
    return args.sort();
}

for brownie points:

Array.prototype.slice is the slice method belonging to all instances of Array as this is coming from the prototype (or cookie cutter) of Arrays.

.call and .apply can be used to apply a function from another object as if it were a part of the object being called upon.

OtherObj.prototype.someFuntion.call(yourobject,arg1) would use yourobject as this in someFunction. You're essentially changing the context of the function.

see: https://developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Global_Objects/Function/apply and https://developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Global_Objects/Function/call

Answer 2

If you're using jQuery, the following is a good deal easier to remember in my opinion:

function sortArgs(){
  return $.makeArray(arguments).sort();
}

Answer 3

To golf:

function sortArgs(){ return [].slice.call(arguments).sort() }

// Returns the arguments object itself
function sortArgs(){ return [].sort.call(arguments) }

Some array methods are intentionary made not to require the target object to be an actual array. They only require the target to have a property named length and indices (which must be zero or larger integers).

[].sort.call({0:1, 1:0, length:2}) // => ({0:0, 1:1, length:2})