Generate Unique Random String With Letters And Numbers In Lower Case

Question

How can I fix this code so it generates unique random letters and numbers in lower case?

api_string = (0...32).map{65.+(rand(25)).chr}.join    

Answer 1

CHARS = (?0..?9).to_a + (?a..?z).to_a
api_string = 32.times.inject("") {|s, i| s << CHARS[rand(CHARS.size)]}