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ctype_graph> <ctype_cntrl
[edit] Last updated: Fri, 10 Feb 2012

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ctype_digit

(PHP 4 >= 4.0.4, PHP 5)

ctype_digitVérifie qu'une chaîne est un entier

Description

bool ctype_digit ( string $text )

ctype_digit() vérifie si tous les caractères de la chaîne text sont des chiffres.

Liste de paramètres

text

La chaîne testée.

Valeurs de retour

Retourne TRUE si tous les caractères de text sont des entiers, FALSE sinon.

Historique

Version Description
5.1.0 Avant PHP 5.1.0, cette fonction retournait TRUE lorsque le paramètre text était une chaîne vide.

Exemples

Exemple #1 Exemple avec ctype_digit()

<?php
$strings 
= array('1820.20''10002''wsl!12');
foreach (
$strings as $testcase) {
  if (
ctype_digit($testcase)) {
    echo 
"La chaîne $testcase ne contient que des entiers.\n";
  } else {
    echo 
"La chaîne $testcase ne contient pas que des entiers.\n";
  }
}
?>

L'exemple ci-dessus va afficher :

La chaîne 1820.20 ne contient pas que des entiers.
La chaîne 10002 ne contient que des entiers.
La chaîne wsl!12 ne contient pas que des entiers.

Exemple #2 Exemple avec ctype_digit() pour comparer des chaînes et des nombres

<?php

$numeric_string 
'42';
$integer        42;

ctype_digit($numeric_string);  // true
ctype_digit($integer);         // false (ASCII 42 correspond au caractère *)

is_numeric($numeric_string);   // true
is_numeric($integer);          // true
?>

Notes

Note:

Cette fonction attend une chaîne afin d'être pertinente ; par exemple, le fait de passer un entier ne retournera pas le résultat attendu. Voir aussi la section sur les types de ce manuel.

Note:

Si un entier dans l'intervalle -128 et 255 inclus est fourni, il sera interprété comme la valeur ASCII d'un seul caractère (les valeurs négatives se verront ajouter 256 afin d'autoriser les caractères dans l'intervalle ASCII étendue). Tout autre entier sera interprété comme une chaîne de caractères contenant les décimales de l'entier.

Voir aussi

  • ctype_alnum() - Vérifie qu'une chaîne est alphanumérique
  • ctype_xdigit() - Vérifie qu'un caractère représente un nombre hexadécimal
  • is_numeric() - Détermine si une variable est un type numérique
  • is_int() - Détermine si une variable est de type nombre entier
  • is_string() - Détermine si une variable est de type chaîne de caractères



ctype_graph> <ctype_cntrl
[edit] Last updated: Fri, 10 Feb 2012
 
add a note add a note User Contributed Notes ctype_digit
Skippy 25-Oct-2011 01:44
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;
}
?>
portalpress dot org at gmail dot com 22-May-2011 08:24
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 12:44
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 05-Feb-2010 05:38
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 08:41
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 02:18
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 02-Aug-2009 12:17
Remove all non-printable characters from a string:
<?php
$str
= implode('', array_filter(str_split($str, 1), 'ctype_print'));
?>
Peter de Pijd 18-Jul-2009 03:53
Note that an empty string is also false:
ctype_digit("") // false
a_p_leeming at hotmail dot com 24-May-2009 06:17
Also note that

<?php ctype_digit("-1");   //false ?>
raul dot 3k at gmail dot com 09-Apr-2009 08:21
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 01:56
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 07:43
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;
}
?>

 
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