JavaScript: The Definitive Guide, Fourth Edition

Name

Arguments — arguments and other properties of a function

Availability

JavaScript 1.1; JScript 2.0; ECMAScript v1

Inherits from/Overrides

Inherits from Object

Synopsis

arguments
arguments[n]

Elements

The Arguments object is defined only within a function body. Although it is not technically an array, the Arguments object has numbered properties that function as array elements and a length property that specifies the number of array elements. Its elements are the values that were passed as arguments to the function. Element 0 is the first argument, element 1 is the second argument, and so on. All values passed as arguments become array elements of the Arguments object, whether or not those arguments are given names in the function declaration.

Properties

callee

A reference to the function that is currently executing.

length

The number of arguments passed to the function and the number of array elements in the Arguments object.

Description

When a function is invoked, an Arguments object is created for it and the local variable arguments is automatically initialized to refer to that Arguments object. The main purpose of the Arguments object is to provide a way to determine how many arguments were passed to the function and to refer to unnamed arguments. In addition to the array elements and length property, however, the callee property allows an unnamed function to refer to itself.

For most purposes, the Arguments object can be thought of as an array with the addition of the callee ...