ctype_alpha

Description

Returns TRUE if every character in text is a letter from the current locale, FALSE otherwise. In the standard C locale letters are just [A-Za-z] and ctype_alpha() is equivalent to (ctype_upper($text) || ctype_lower($text)) if $text is just a single character, but other languages have letters that are considered neither upper nor lower case.

例子 1. A ctype_alpha() example (using the default locale) <?php $strings = array('KjgWZC', 'arf12'); foreach ($strings as $testcase) {     if (ctype_alpha($testcase)) {         echo "The string $testcase consists of all letters.\n";     } else {         echo "The string $testcase does not consist of all letters.\n";     } } ?> This example will output : The string KjgWZC consists of all letters. The string arf12 does not consists of all letters.

See also ctype_upper(), ctype_lower(), and setlocale().