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ReDim StatementIf you use the Preserve keyword, you can resize only the last array dimension and you can't change the number of dimensions at all. For example, if your array has only one dimension, you can resize that dimension because it is the last and only dimension. However, if your array has two or more dimensions, you can change the size of only the last dimension and still preserve the contents of the array . The following example shows how you can increase the size of the last dimension of a dynamic array without erasing any existing data contained in the array.

ReDim X(10, 10, 10)
. . .
ReDim Preserve X(10, 10, 15)

В многомерных массивах можно менять только последнее измерение с сохранение содержимого массива.