An array-like object corresponding to the arguments passed to a function. The arguments object is a local variable available within all functions.
You can refer to a function's arguments within the function by using the arguments object. This object contains an entry for each argument passed to the function, the first entry's index starting at 0.
The arguments can also be set:
arguments[1] = 'new value';
The arguments object is not an array. It is similar to an array, but does not have any array properties except length. For example, it does not have the pop method. However it can be converted to an real array:
var args = Array.prototype.slice.call(arguments);
You can use the arguments object if you call a function with more arguments than it is formally declared to accept. This technique is useful for functions that can be passed a variable number of arguments. You can use arguments.length to determine the number of arguments passed to the function, and then process each argument by using the arguments object. (To determine the number of arguments declared when a function was defined, use the Function.length property.)
