length Property (Function)

function

Required. The name of the currently executing Function object.

The length property of a function is initialized by the scripting engine to the number of arguments in the function's definition when an instance of the function is created.

What happens when a function is called with a number of arguments different from the value of its length property depends on the function.

The following example illustrates the use of the length property:

function ArgTest(a, b)
{
    var s = "Expected Arguments: " + ArgTest.length;
    return (s);
}

Version 2

Reference