ctype_cntrl
If you need to check for integers instead of just digits you can supply your own function such as this:
<?php
function ctype_int($text)
{
return preg_match('/^-?[0-9]+$/', (string)$text) ? true : false;
}
?>
ctype_digit
(PHP 4 >= 4.0.4, PHP 5)
ctype_digit — Check for numeric character(s)
Descrierea
bool ctype_digit
( string $text
)
Checks if all of the characters in the provided string, text, are numerical.
Parametri
- text
-
The tested string.
Valorile întoarse
Returns TRUE if every character in the string text is a decimal digit, FALSE otherwise.
Istoria schimbărilor
| Versiunea | Descriere |
|---|---|
| 5.1.0 | Before PHP 5.1.0, this function returned TRUE when text was an empty string. |
Exemple
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";
}
}
?>
Exemplul de mai sus va afișa:
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($integer); // false (ASCII 42 is the * character)
is_numeric($numeric_string); // true
is_numeric($integer); // true
?>
Note
Notă:
This function expects a string to be useful, so for example passing in an integer may not return the expected result. However, also note that HTML forms will result in numeric strings and not integers. See also the types section of the manual.
Notă:
If an integer between -128 and 255 inclusive is provided, it is interpreted as the ASCII value of a single character (negative values have 256 added in order to allow characters in the Extended ASCII range). Any other integer is interpreted as a string containing the decimal digits of the integer.
Vedeți de asemenea
- ctype_alnum() - Check for alphanumeric character(s)
- ctype_xdigit() - Check for character(s) representing a hexadecimal digit
- is_numeric() - Determină dacă o variabilă este un număr sau un string numeric
- is_int() - Determină dacă tipul unei variabile este integer
- is_string() - Determină dacă tipul variabilei este string
add a note
User Contributed Notes
ctype_digit
Skippy
24-Oct-2011 07:44
portalpress dot org at gmail dot com
22-May-2011 02:24
To my surprise after one million iterations:
It took 0.5646638 seconds to false if(('abc'*1 . '')==='abc')
It took 0.5725240 seconds to true if(('123'*1 . '')==='123')
It took 0.3741021 seconds to false if((('abc'*1) . '')==='abc')
It took 0.4357590 seconds to true if((('123'*1) . '')==='123')
It took 0.3529291 seconds to false ctype_digit('abc')
It took 0.3391420 seconds to true ctype_digit('123')
The function ctype_digit() is faster then an inline if().
But this test also shows the value of ((first*1) . second).
mdsky at web dot de
21-May-2010 06:44
is_numeric gives true by f. ex. 1e3 or 0xf5 too. So it's not the same as ctype_digit, which just gives true when only values from 0 to 9 are entered.
John Saman
04-Feb-2010 10:38
Using is_numeric function is quite faster than ctype_digit.
is_numeric took 0.237 Seconds for one million runs. while ctype_digit took 0.470 Seconds.
strrev xc tod noxeh ta ellij
14-Dec-2009 01:41
ctype_digit() will treat all passed integers below 256 as character-codes. It returns true for 48 through 57 (ASCII '0'-'9') and false for the rest.
ctype_digit(5) -> false
ctype_digit(48) -> true
ctype_digit(255) -> false
ctype_digit(256) -> true
(Note: the PHP type must be an int; if you pass strings it works as expected)
walter
09-Dec-2009 07:18
I was looking at whether this would save time on the numerous input validations I make in legions of scripts. Typically I use a function numbers_only() which simply does a preg_replace() to remove non-digits from a string.
To test for a possible speedup, I created a new function which only performed the preg_replace() once a type_digit() check had failed.
The results for 1 million interations showed that using ctype_digit() beforehand caused approximately 1/3rd additional latency on strings that were going to be preg_replace()'d anyway (ie: strings that did not contain only digits). It caused an over 100% speedup over that (latency inclusive) time for input strings that were pure numbers. The speedup was around 2/3 of the original blind preg_replace().
The lesson for me is that it's only worth trying to optimise away preg_replace() using ctype_digit() or similar if you know with some certainty that the vast majority of your inputs will lean one way or the other.
Having said that, ctype_digit() seems to be cosnistently 30% faster than preg_match(). But adding the additional PHP option as a requirement for your codebase may not justify the optimisation.
Let's face it: PHP aint exactly assembler, even if it is much faster than ruby :)
Chris
01-Aug-2009 06:17
Remove all non-printable characters from a string:
<?php
$str = implode('', array_filter(str_split($str, 1), 'ctype_print'));
?>
Peter de Pijd
17-Jul-2009 09:53
Note that an empty string is also false:
ctype_digit("") // false
a_p_leeming at hotmail dot com
24-May-2009 12:17
Also note that
<?php ctype_digit("-1"); //false ?>
raul dot 3k at gmail dot com
09-Apr-2009 02:21
The ctype_digit can be used in a simple form to validate a field:
<?php
$field = $_POST["field"];
if(!ctype_digit($field)){
echo "It's not a digit";
}
?>
Note:
Digits is 0-9
Anonymous
19-Nov-2008 06:56
Indeed, ctype_digit only functions correctly on strings. Cast your vars to string before you test them. Also, be wary and only use ctype_digit if you're sure your var contains either a string or int, as boolean true for ex will convert to int 1.
To be truly safe, you need to check the type of the var first. Here's a wrapper function that improves upon ctype_digit's broken implementation:
<?php
// replacement for ctype_digit, to properly
// handle (via return value false) nulls,
// booleans, objects, resources, etc.
function ctype_digit2 ($str) {
return (is_string($str) || is_int($str) || is_float($str)) &&
ctype_digit((string)$str);
}
?>
If, like me, you're not willing to take a chance on ctype_digit having other problems, use this version:
<?php
// replacement for ctype_digit, to properly
// handle (via return value false) nulls,
// booleans, objects, resources, etc.
function ctype_digit2 ($str) {
return (is_string($str) || is_int($str) || is_float($str)) &&
preg_match('/^\d+\z/', $str);
}
?>
minterior at gmail dot com
10-Sep-2007 01:43
I use ctype_digit() function as a part of this IMEI validation function.
<?php
/**
* Check the IMEI of a mobile phone
* @param $imei IMEI to validate
*/
function is_IMEI_valid($imei){
if(!ctype_digit($imei)) return false;
$len = strlen($imei);
if($len != 15) return false;
for($ii=1, $sum=0 ; $ii < $len ; $ii++){
if($ii % 2 == 0) $prod = 2;
else $prod = 1;
$num = $prod * $imei[$ii-1];
if($num > 9){
$numstr = strval($num);
$sum += $numstr[0] + $numstr[1];
}else $sum += $num;
}
$sumlast = intval(10*(($sum/10)-floor($sum/10))); //The last digit of $sum
$dif = (10-$sumlast);
$diflast = intval(10*(($dif/10)-floor($dif/10))); //The last digit of $dif
$CD = intval($imei[$len-1]); //check digit
if($diflast == $CD) return true;
return false;
}
?>