The arguments object

arguments.length

• argLength('foo', 'bar') →
• argLength('foo', 'bar', 1, 2, 3) →
• argLength(new Array('foo', 'bar'))→
• argLength(1, 2, 3) →

Function.arguments.length

• funcArgLength('foo', 'bar') →

for (var i = 0; i < arguments.length; i++)

forNormalLoop('foo', 'bar', 'baz');

for (arg in arguments)

forInArgs('foo', 'bar', 'baz');

This should not create a list, because all properties have { DontEnum } as an attribute.

arguments.callee

Handy for recursive functions.

A factorial method

Math.fact = function(i) {
  if (i > 0) {
    return i * arguments.callee(i - 1);
  } else {
    return 1;
  }
}

• Math.fact(4) →
• Math.fact(10) →
• Math.fact(99) →
• Math.fact(3) →
• Math.fact() →