Revision [13722]
This is an old revision of KeyPgPreserve made by CountingPine on 2008-09-11 13:09:27.
PRESERVE
Used with KeyPgRedim Redim to preserve contents will resizing an array
Syntax:
Description:
Used with KeyPgRedim Redim so that when an array is resized, data is not reset but is preserved. This means when the array is enlarged that only new data is reset, while the old data remains the same.
NOTE: Redim KeyPgPreserve Preserve may not work as expected in all cases:
KeyPgPreserve Preserve's current behavior is to keep the original data contiguous in memory, and only expand or truncate the size of the memory.
Its behavior is only well-defined when the upper bound is changed. If the lower bound is changed, the current result is that the data is in effect shifted to start at the new lower bound.
If there are multiple dimensions, only the upper bound of the first dimension may be changed safely. If lower-order dimensions are resized at all, the effects can be hard to predict.
Its behavior is only well-defined when the upper bound is changed. If the lower bound is changed, the current result is that the data is in effect shifted to start at the new lower bound.
If there are multiple dimensions, only the upper bound of the first dimension may be changed safely. If lower-order dimensions are resized at all, the effects can be hard to predict.
Examples:
ReDim array(1 To 3) As Integer
Dim i As Integer
array(1) = 10
array(2) = 5
array(3) = 8
ReDim Preserve array(1 To 10)
For i = 1 To 10
Print "array("; i; ") = "; array(i)
Next
Dim i As Integer
array(1) = 10
array(2) = 5
array(3) = 8
ReDim Preserve array(1 To 10)
For i = 1 To 10
Print "array("; i; ") = "; array(i)
Next
Differences from QB:
- Preserve wasn't supported until PDS 7.1
See also:
Back to Array Functions
