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Arguments : Object
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An array of parameters passed to a function.

Platform Support

IE	Mozilla	Netscape	Opera	Safari
4.0+	1.0+	3.0+	7.0+	1.0+

Constructors

Constructor

Action

IE

Mozilla

Netscape

Opera

Safari

Arguments Constructor() : Arguments

Creates a new instance of the Arguments array.

4.0+

1.0+

3.0+

7.0+

1.0+

Properties

Property	Action	IE	Mozilla	Netscape	Opera	Safari
callee : String Name of the function being executed.	Show Details	5.5+	1.0+	4.0+	7.0+	no
Example: Using `arguments.callee` in an anonymous recursive function A recursive function must be able to refer to itself. Typically, a function refers to itself by its name. However, an anonymous function does not have a name, and if there is no accessible variable referring to it, i.e. the function is not assigned to any variable, the function cannot refer to itself. (Anonymous functions can be created by a function expression or the `Function` constructor.) This is where `arguments.callee` comes in. The following example defines a function, which, in turn, defines and returns a factorial function. function makeFactorialFunc() { alert('making a factorial function!'); return function(x) { if (x <= 1) return 1; return x * arguments.callee(x - 1); }; } var result = makeFactorialFunc()(5); // returns 120 (5 * 4 * 3 * 2 * 1) Remarks `callee` is a property of the arguments local variable available within all function objects; `callee` as a property of `Function.arguments` is no longer used. (`Function.arguments` itself is also deprecated.) `arguments.callee` allows anonymous functions to refer to themselves, which is necessary for recursive anonymous functions. The `this` keyword does not refer to the currently executing function. Use the `callee` property to refer to a function within the function body. Availability JavaScript 1.2\|Deprecated by JavaScript 1.4\|JScript 5.5\|ECMAScript v1
caller : String Name of the function that called the function being executed.	Show Details	4.0+	1.0	3.0+	no	no
Example: Checking the value of `arguments.caller` in a function The following code checks the value of `arguments.caller` in a function. function myFunc() { if (arguments.caller == null) { return ("The function was called from the top!"); } else return ("This function's caller was " + arguments.caller); } Remarks `arguments.caller` can no longer be used. Use the non-standard `caller` property of the function instead. The `caller` property is available only within the body of a function. If the currently executing function was invoked by the top level of a JavaScript program, the value of `caller` is null. The `this` keyword does not refer to the currently executing function, so you must refer to functions and `Function` objects by name, even within the function body. The `caller` property is a reference to the calling function, so: If you use it in a string context, you get the result of calling `functionName.toString`, i.e. the decompiled canonical source form of the function. You can also call the calling function, if you know what arguments it might want. Thus, a called function can call its caller without knowing the name of the particular caller, provided it knows that all of its callers have the same form and fit, and that they will not call the called function again unconditionally (which would result in infinite recursion). Availability JavaScript 1.2\|Deprecated by JavaScript 1.3
length : Number Number of arguments passed to the function.	Show Details	4.0+	1.0+	3.0+	7.0+	1.0+
See Also Array.length\|Function.length Availability JavaScript 1.1\|JScript 2\|ECMAScript v1

References

Availability

JavaScript 1.1|JScript 2.0|ECMAScript v1