Java String isAlpha() Utility Method

Java String Utility Methods


This page contains the source code of Java String isAlpha() utility method - This method checks if the CharSequence contains only Unicode letters.

Java String isAlpha() Utility Method

The following String isAlpha() utility method checks if the CharSequence contains only Unicode letters:
/**
 * <p>
 * Checks if the CharSequence contains only Unicode letters.
 * </p>
 *
 * <p>
 * {@code null} will return {@code false}. An empty CharSequence
 * (length()=0) will return {@code false}.
 * </p>
 * 
 * @param cs
 *            the CharSequence to check, may be null
 * @return {@code true} if only contains letters, and is non-null
 * @since 3.0 Changed signature from isAlpha(String) to
 *        isAlpha(CharSequence)
 * @since 3.0 Changed "" to return false and not true
 */
public static boolean isAlpha(final CharSequence cs) {
    if (isEmpty(cs)) {
        return false;
    }
    final int sz = cs.length();
    for (int i = 0; i < sz; i++) {
        if (!Character.isLetter(cs.charAt(i))) {
            return false;
        }
    }
    return true;
}





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