lowerCaseLettersOnly method

String lowerCaseLettersOnly()

Extracts only ASCII lowercase letter characters (a-z) from this string.

Removes all characters that are not lowercase ASCII letters using a regex. Uppercase letters and Unicode characters are removed.

Returns: A new string containing only lowercase ASCII letters, or empty if none found.

Example:

'Hello123World!'.lowerCaseLettersOnly(); // 'elloorld'
'ABC-def'.lowerCaseLettersOnly(); // 'def'
'123'.lowerCaseLettersOnly(); // ''

Implementation

String lowerCaseLettersOnly() {
  if (isEmpty) return '';
  return replaceAll(RegExp(r'[^a-z]'), '');
}