Question

I want to generate unique numbers so that I can use them as reference numbers to handle my client requests.

I dont want the numbers to be repeated neither am i using any database to store the numbers.

I simply want to use a simple algorithm to generate random numbers.

I am using something like

rand(10*45, 100*98)

Is it possible to do something like that.
I know my requirement seems quite odd, but I just want to know if its possible.

Answer 1

Why not just preface your random number with a Unix timestamp? This will ensure uniqueness.

$random = time() . rand(10*45, 100*98);

Otherwise, you can store your numbers in a file. If you can, store them in a database.