Turning a functions arguments into an array

args.js

var test = function(){
  var args = arguments;
  args.push(4);
  console.log(args);
}

// Results in a TypeError, as arguments isn't actually an array object.
// To coerce arguments to an array, call Array's slice method:

var test = function(){
  var args = Array.prototype.slice.call(arguments);
  args.push(4);
  console.log(args);
}