This may end up being a trivial question – I know I’m going to need to do this soon for an app I’m working on, but haven’t really worked on it myself yet – I’m really just floating it to see if there’s an obvious method I’m missing.
Basically, what I need is to generate a sequence of numbers using a-z, A-Z, 0-9, except without vowels. There is a small chance I will need to make it unpredictable, so being able to generate out of order is a bonus.
I’m initially thinking for each new one to just work forward from the last no-vowel match until I find the next one (or generate random numbers until I get one I don’t have already in the case of unpredictable values), but is there a better way? Perhaps a baseX number system obj that allows you to specify the allowable characters?
Using PHP/MySQL if it matters.
There’s a function in an answer of mine here that can convert from any base to any other and which lets you customize the digit pool; it also works on arbitrary-sized input. You can generate a sequence in base 10 and convert to whatever you need.