You can define arrays of variables in single and multiple dimensions like
dim lines(5) as string
dim cells(5,10) as string
where lines is an array of 6 elements going from 0 to 5. You can also define an empty array with
dim lines(-1) as string
Later in the code, you can either use the redim statement
redim cells(10,20) as string
redim lines(0) as string
If you try to access an array element which is not in the dimension, you will get an "Out of Bounds Exception".