Newbie Problem with Multidimensional Arrays in JavaScript

I recently wrote code to import and parse data in AS3 from a CSV file. My psucdo-code

• Each row of the CSV file has it's individual elements pushed into a new array.

• That array is then pushed into an array, creating a multidimensional array.

Because the length of each row, and however many rows there are are completely dynamic and depends on what my client enters into the CSV file, I have no way of knowing the total amount (and it's not a perfect square) until the information has been imported and parsed.

This is what I have so far:

 static var myDataString:String[];
 static var myData:Array = new Array();
 
 function LoadData()
 {
     var dataStream:StreamReader = new StreamReader('SessionData.csv');
     var dataContents = dataStream.ReadToEnd();
     dataStream.Close();
     
     //This is a string that has organized the data into the appropriate rows, but now we need the correct columns too.
     myDataString = dataContents.Split('\r\n'[0]);//Splits Data into Appropriate Rows
     
     //print('What is in my Data String?  Let us find out!!');
     for(var i:int=0;i<=myDataString.Length-1;i++)
     {
         //print('---');
         //print('This is Row '+i+' of the Data String:');
         //print(myDataString[i]);
         //Sort Rows into their Columns
         var rowArray:Array = new Array();
         rowArray = myDataString[i].Split(','[0]);
         //print('Entire Row: '+rowArray);
         //print('First Item in Row: '+rowArray[0]);
         //Place the entire row array back into the larger data array to make a multidimensional array
         myData.push(rowArray);
     }
     print('Data Length: '+myData.length);
     //print('Row 0 Length: '+myData[0].length);
     print('Entire Data:');
     print(myData);
     print('--- End Data ---');
     print('3rd Row in Data:');
     print(myData[2]);
     print('2nd Element in 3rd Row in Data');
     print(myData[2][1]);
     
 }

And here is an example of what prints out from this madness:

• Data Length 7

• Second Row Length: 18

• Entire Data:

• Session ID Number,Grid Size (0= Previous Grid Size),Number of Trials,Number of Targets (Must be less than the Number of Trials),Number of L Blocks per Trial (Must be less than the Grid Size squared),Movement Rate,Scale Rate,Start Position,End Position, 1,3,3,1,2,1,1,0,0, 2,3,3,2,3,1,1,0,0, 3,3,3,1,5,1,1,0,0, 4,3,3,1,4,1,1,0,0, 5,3,3,1,3,1,1,0,0,

• --- End Data---

• 3rd Row in Data:

• 2,3,3,2,3,1,1,0,0

• 2nd Element in 3rd Row in Data

Then finally, the last line throws an error "BCE0048: Type 'Object' does not support splicing." (in fact, the program won't run because of this error). And that's the friendliest error I've received after several methods. I am not keen on how the String[] variable type works. I'm not really even sure of what it is. I only found it working in other threads that were similar to my problem, and was using trial and error to get it working.

In the other languages (python and AS3), I can access a single element in a multidimensional array by using that line myData[2][1], but obviously the JS in Unity doesn't like it. If I know the index numbers in my arrays (essentially the row, then column number), how can I access the element?

P.S. The print statements that are commented out inside the for-loop were to prove that each row was separated into the elements in an array before being pushed into my big, master array.

Thanks!