An Array isn't really a data type, but a container that holds more than one value, such as point coordinate values. Arrays identify their members by an index number, which starts at 0. So the first member in an array is the item at index 0, the second member is the item at index 1, and so on.
For C#, the System.Array class supports multidimensional arrays. SAFEARRAYs are generally returned wrapped in a System.Object object (roughly corresponding to a Variant) containing the System.Array object.
For JScript, you can convert SAFEARRAYs to native JScript arrays using the VBScript.toArray() method (see msdn.microsoft.com/library/default.asp?url=/library/en-us/jscript7/html/jsmthtoarray.asp). For more information, see Working with Arrays (and Other Collections) in Softimage.