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  • LetterQ[ string ] yields True if all the characters in the string are letters, and yields False otherwise.
  • LetterQ[ string ] by default gives False if string contains any space or punctuation characters.
  • LetterQ handles both ordinary and special characters.
  • LetterQ treats as letters all special characters explicitly listed as letters in the table in Section A.12.1.
  • In general, LetterQ treats as letters all characters that appear as ordinary text in any language.
  • LetterQ treats as letters such special characters as , , and æ.
  • LetterQ does not treat as letters (\[EmptySet], ℏ (\[HBar]), (\[Angstrom] or (\[Sum]).
  • See the Mathematica book: Section 2.7.4.
  • See also: DigitQ, UpperCaseQ, LowerCaseQ, CharacterRange.

    Further Examples

    All the characters have to be letters.