An array of parameters passed to a function.
Platform Support
Constructors
Creates a new instance of the Arguments array.
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4.0+ |
1.0+ |
3.0+ |
7.0+ |
1.0+ |
Arguments() : Arguments
Creates a new instance of the Arguments array.
Returns
- Visibility
- internal
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Properties
Name of the function being executed.
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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
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JavaScript 1.2|Deprecated by JavaScript 1.4|JScript 5.5|ECMAScript v1
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Name of the function that called the function being executed.
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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
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Number of arguments passed to the function.
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Show Details |
4.0+ |
1.0+ |
3.0+ |
7.0+ |
1.0+ |
- See Also
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Array.length|Function.length
- Availability
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JavaScript 1.1|JScript 2|ECMAScript v1
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References
Function
Availability
JavaScript 1.1|JScript 2.0|ECMAScript v1