Hi All

Could you please help me with this because I am going round the bend.

In essence, I'm working with the following type of array:

arrNames(x,y)
x always equals 0 in this case because I'm working with 1 dim here
y is variable as the data I put in it is from an Access table, so this might
range from 0 to 5

All I want to do is get 2 random indexs from this array, but it always seems
to select 0 or 1 even if 'y' is set to 3, ie 0 to 3.

My random code is as follows:

bytNameSeed1 = Int(((UBound(arrNames, 2) - LBound(arrNames, 2)) * Rnd) +
LBound(arrNames, 2))

Do
  bytNameSeed2 = Int(((UBound(arrNames, 2) - LBound(arrNames, 2)) * Rnd) +
LBound(arrNames, 2))
Loop Until bytNameSeed2 <> bytNameSeed1

For some reason if y has say 3 values in it (ie 0 - 2) then the above always
manages to pick 0 and 1 or 1 and 0, but never 2.

What's worse is that if y has onlt 2 values (ie 0 - 1) then it might get the
first random value OK, ie 0 or 1, but to get the other one in the second
random run (ie 1 or 0) it appears to go in an infinite loop.

All I want is for it to work with the numbers that are available to it so
that:

a) if y has say 4 values (ie 0 - 3) then there is the possibility that it
will produce 2 random numbers out of the 4 available not just 0 and 1.

b) More importantly it won't go into an infinite loop if there are only 2
options available (ie 0 and 1).  I would have thought this smaller range
would have made my routine quicker, but it makes it worse.

Any ideas?

Show quote Hide quote According to VB help files for the Rnd function, the formula for getting
a random number within a range is this...

     Int((upperbound - lowerbound + 1) * Rnd + lowerbound)

Your formula appears to be missing the "+1" part. If you are always
using zero based arrays, you then the LBound is 0 and you can simply
remove it from the calculation. Also, if your first dimension is always
0 making it a one-dimensional array, why not use an actual
one-dimensional array....

     Dim arrNames()
     ReDim arrNames(5)
     bytNameSeed1 = Int((Ubound(arrNames) + 1) * Rnd)

Rick - MVP

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