Tell if string contains a-z chars [duplicate]

Answer 1

In addition to regular expressions, and assuming you actually want to know if the String doesn't contain only characters, you can use Character.isLetter(char) -

boolean hasNonLetters = false;
for (char ch : s.toCharArray()) {
  if (!Character.isLetter(ch)) {
    hasNonLetters = true;
    break;
  }
}
// hasNonLetters is true only if the String contains something that isn't a letter -

From the Javadoc for Character.isLetter(char),

A character is considered to be a letter if its general category type, provided by Character.getType(ch), is any of the following:

UPPERCASE_LETTER
LOWERCASE_LETTER
TITLECASE_LETTER
MODIFIER_LETTER
OTHER_LETTER