Javascript add extra argument

Question

Lets take a look at this code:

var mainFunction = function() {
  altFunction.apply(null, arguments);
}

The arguments that are passed to \"mainF

Answer 1

The arguments "array" isn't an array (it's a design bug in JavaScript, according to Crockford), so you can't do that. You can turn it into an array, though:

var mainFunction = function() {
  var mainArguments = Array.prototype.slice.call(arguments);
  mainArguments.push('extra data');

  altFunction.apply(null, mainArguments);
}