(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 the string text is a decimal digit, FALSE otherwise.
| 版本 | 说明 |
|---|---|
| 5.1.0 | Before PHP 5.1.0, this function returned TRUE when text was an empty string. |
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";
}
}
?>
以上例程会输出：
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.
Example #2 A ctype_digit() example comparing strings with integers
<?php
$numeric_string = '42';
$integer = 42;
ctype_digit($numeric_string); // true
ctype_digit($integer); // false
is_numeric($numeric_string); // true
is_numeric($integer); // true
?>
Note:
This function requires a string to be useful, so for example passing in an integer will always return FALSE. However, also note that HTML forms will result in numeric strings and not integers. See also the types section of the manual.