initializing a 2D array in google apps script

Trying code like:

var resultasarray = [];  

  

  while (TableData.next()) {

    for (var j = 0; j < numberOfColumns; j++) {

       resultasarray[i][j] = TableData.getString(j+1));

  }

  i++;

       

    }

threw errors, TypeError: Cannot read properties of undefined (reading '0')

Using push() instead, worked.

var resultasarray = [];  

  

  while (TableData.next()) {

    var rowvals = [];

    for (var j = 0; j < numberOfColumns; j++) {

        rowvals.push(TableData.getString(j+1));

        //Logger.log(TableData.getString(j+1))

    }

    resultasarray.push(rowvals)

    i++;

  }