Rnd [-1] : what is this ?

[raoul]

I have find (in Excel VBA listing) this line:

Rnd [-1]

without other operators. It work well without error, but what it does? I know

a = Rnd (-1)

but I don't know what

Rnd [-1]

means. Can you help me?
Thanks in advance.

[WorkHorse]

Considering that it uses brackets instead of parentheses, you are probably looking at some very old code. In this case, brackets are the same as parentheses.

Passing a negative number to Rnd causes code to ignore a Randomize command that is passed a number so that a later Rnd repeats the same series of "random" numbers. The seed doesn't get reset. You can play around with this:

Rnd (-1)
Randomize (1)
For i = 1 To 3
    Debug.Print Rnd(1)
Next
Debug.Print " "

Note that if you don't pass a number to Randomize, Rnd (-1) has no effect. Using the above code should have the same result as if you didn't have either of the lines before the For statement.