(PHP 4 >= 4.0.4, PHP 5)
ctype_digit — Check for numeric character(s)
Checks if all of the characters in the provided string, text , are numerical.
The tested string.
Returns TRUE if every character in text is a decimal digit, FALSE otherwise.
Example#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";
}
}
?>
上例将输出：
The string 1820.20 does not consist of all digits. The string 10002 consists of all digits. The string wsl!12 does not consist of all digits.