Availability
Flash Player 5.

Usage

 myArray  .join([  separator  ]) 

Parameters
separator A character or string that separates array elements in the returned string. If you omit this parameter, a comma is used as the default separator.

Returns
String.

Description
Method; converts the elements in an array to strings, inserts the specified separator between the elements, concatenates them, and returns the resulting string. A nested array is always separated by a comma, not by the separator passed to the join method.

Example
The following example creates an array with three elements: Earth, Moon, and Sun. It then joins the array three times—first using the default separator (a comma and a space), then using a dash, and then using a plus sign (+)—and displays them in the Output window:

a = new Array("Earth","Moon","Sun")
trace(a.join()); 
// returns Earth, Moon, Sun
trace(a.join(" - ")); 
// returns Earth - Moon - Sun
trace(a.join(" + ")); 
// returns Earth + Moon + Sun