Groovy adds a couple of methods to the Character
class to determine of the character is a letter, digit, whitespace, upper- or lowercase.
def str = 'a1cB \n.9' def characters = str.chars // Convert to char[] assert characters[0].isLetter() // 'a' assert characters[1].isDigit() // '1' assert characters[2].isLowerCase() // 'c' assert characters[3].isUpperCase() // 'B' assert characters[4].isWhitespace() // ' ' assert characters[5].isWhitespace() // '\n' assert !characters[6].isLetterOrDigit() // '.' assert characters[7].isLetterOrDigit() // '9'