Regex to check alphanumeric string in ruby

Question

I am trying to validate strings in ruby. Any string which contains spaces,under scores or any special char should fail validation. The valid string should contain only chars a-z

Answer 1

Similar to @rohit89:

VALID_CHARS = [*?a..?z, *?A..?Z, *'0'..'9']
  #=> ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m",
  #    "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z",
  #    "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M",
  #    "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z",
  #    "0", "1", "2", "3", "4", "5", "6", "7", "8", "9"]

def all_valid_chars?(str)
  a = str.chars
  a == a & VALID_CHARS
end

all_valid_chars?('a9Z3')  #=> true
all_valid_chars?('a9 Z3') #=> false