Better way to concat function arguments with an extra value

Question

I've the following situation: I want to prepend (unshift) the arguments given to an function by another parameter. How my current approach looks like:

function eventReferer(event) {
  var self = this;

  return function() {
    var args = ([event]).concat(Array.prototype.slice.call(arguments, 0, arguments.length));
    return eventFunction.apply(self, args);
  };
}

"eventFunction" is a custom function. I need to redirect the called event + all arguments to this function.

Because "arguments" is no valid Array in Javascript, the method of Array will not work. Is there any better way to merge my event and the arguments to a new array?

You can convert arguments to array as per latest ECMA standards. http://stackoverflow.com/questions/960866/converting-the-arguments-object-to-an-array-in-javascript http://stackoverflow.com/questions/1316371/converting-a-javascript-array-to-a-function-arguments-list — vivek_nk, Apr 08 '14 at 10:50
Okay, that's exactly what I'm doing above. So there is no other way of doing this? — SuperNova, Apr 08 '14 at 12:08
However, I'd only inspected the accepted answer, but the other answers are going deeper into detail. I tried the testcase on http://jsperf.com/ghel-args and selected the best version for my environment. — SuperNova, Apr 08 '14 at 12:40

score 0 · Accepted Answer · answered Apr 08 '14 at 12:42

There are some more ways shown in the benchmark on http://jsperf.com/ghel-args - The only thing that's to do, is to unshift the "event" param to the array after converting the arguments to a regular JS-Array using one of the functions. So my first approach was correct, but not ideal (because it's not the fastest method available).

Better way to concat function arguments with an extra value

1 Answers1