Here a code i wrote for generating alphanumeric code in “youtube style”. This code automatically increment using a..z, A..Z, 0..9:
def generate_code
carry = false
for i in 1..(shorturl.length) do
shorturl = “aaZ9″ #this is your starting string
index = shorturl.length – i
if index == shorturl.length – 1
char = shorturl[index]
char = char + 1
if char == 123
char = 65
elsif char == 91
char = 48
elsif char == 58
char = 97
carry = true
end
shorturl[index] = char
elsif carry
carry = false
char = shorturl[index]
char = char + 1
if char == 123
char = 65
elsif char == 91
char = 48
elsif char == 58
char = 97
carry = true
end
shorturl[index] = char
end
end
if carry
shorturl = “a” + shorturl
end
puts shorturl
end