Question

This has been driving me crazy for a few days. Why doesn’t the following work?

    Dim arr(3, 3) As Integer      For y As Integer = 0 To arr.GetLength(0) - 1         For x As Integer = 0 To arr.GetLength(y) - 1             arr(y, x) = y + x         Next     Next 

Also, what if the array looked like this instead?

{ {1, 2, 3},   {4, 5, 6, 7, 8, 9, 9, 9},   {5, 4, 3, 2} } 

Answer 1

Ok, so what you really need is a ‘jagged array’. This will allow you to have an ‘array that contains other arrays of varying lengths’.

  Dim arr As Integer()() = {New Integer() {1, 2, 3}, New Integer() {4, 5, 6, 7, 8, 9, 9, 9}, New Integer() {5, 4, 3, 2}}    For x = 0 To arr.GetUpperBound(0)       Console.WriteLine('Row ' & x & ' has ' & arr(x).GetUpperBound(0) & ' columns')       For y = 0 To arr(x).GetUpperBound(0)           Console.WriteLine('(' & x & ',' & y & ') = ' & arr(x)(y))       Next    Next 

Output:

Row 0 has 2 columns (0,0) = 1 (0,1) = 2 (0,2) = 3 Row 1 has 7 columns (1,0) = 4 (1,1) = 5 (1,2) = 6 (1,3) = 7 (1,4) = 8 (1,5) = 9 (1,6) = 9 (1,7) = 9 Row 2 has 3 columns (2,0) = 5 (2,1) = 4 (2,2) = 3 (2,3) = 2