Why the if statement check on the alphabet array in Format.js? about nanoid HOT 5 CLOSED

Because byte could contain number bigger than alphabet length.

For example, if alphabet size i 5 symbols (abcde), nanoid’s random generator will put to byte numbers between 0…7. 0, 1, 2, 3, 4 is correct positions in the alphabet, but 5, 6 will be out of alphabet size.

from nanoid.

Ah, right. For some of the non-default cases.

On an unrelated note, var byte = bytes[i] & mask caused a brief moment of confusion when I was looking at the code. At quick glance, based on the variable names alone, one might expect a variable named byte would be var byte = bytes[i] rather than var byte = bytes[i] & mask. Not a pressing matter, but I believe there's room for improvement in the variable name to eliminate any confusion. *shrug*

from nanoid.

I am open for name suggestion :D.

& mask reduce cases when we ignore byte when it out of alphabet size (so for 5 symbols alphabet byte = bytes[i] will generate numbers between 0…255, but byte = bytes[i] & mask will generate 0..7)

from nanoid.

Right.

Something like alphabetIndex might work? It describes its purpose rather than its origin.

from nanoid.

Or maybe position or char?

from nanoid.