ctype_digit

Description

Returns TRUE if every character in text is a decimal digit, FALSE otherwise.

例子 1. A ctype_digit() example <?php $strings = array('1820.20', '10002', 'wsl!12'); foreach ($strings as $testcase) {     if (ctype_digit($testcase)) {         echo "The string $testcase consists of all digits.\n";     } else {         echo "The string $testcase does not consist of all digits.\n";     } } ?> This example will output : The string 1820.20 does not consists of all digits. The string 10002 consists of all digits. The string wsl!12 does not consists of all digits.

See also ctype_alnum() and ctype_xdigit().