How to change number of elements of two dimensional array in VB?

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I need to read data (maybe numbers or strings) from a file into an array (using VB2019).

The value of the two indices of the array is variable from case to case, i.e., not known at the start. How can I do that? I know that the first index cannot be changed by ReDim, yet I need to do a ReDim on the first index. Any ideas?

What I have tried:

I can determine the number of elements along x & y axes individually.

Posted 7-Feb-22 0:37am

Member 10118655

Updated 8-Feb-22 0:24am

Sean Ewington

v2

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Solution 2

Thanks. Looks like that's the only way.

Posted 8-Feb-22 0:24am

Member 10118655

Updated 9-Feb-22 5:59am

v3

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Tony Hill 8-Feb-22 6:34am

Don't submit a comment or thanks as a solution, submit it as comment.

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OriginalGriff · Accepted Answer · 2022-02-07T00:53:00

You can't, and unless you are using VB6 or earlier, Redim is a pretty bad idea as it creates a new array, which means that "older references" to that data may not be updated. It's also a slow and memory wasting process if your array gets large.

Instead, use a List of (List of object) as they can be expanded or contracted as needed if you can't "know" the number of items in advance. This also has the advantage that the number of items per "row" does not have to be the same - if the file data has 2 items on line one and 6 on line two, it will still cope without reallocation.