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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_digitVerifica se os caracteres são numéricos

Descrição

bool ctype_digit ( string $text )

Verifica se todos os caracteres na string fornecida, text, são numéricos.

Parâmetros

text

A string a ser testada.

Valor Retornado

Retorna TRUE se todos caracteres em text são dígitos decimais, FALSE caso contrário.

Exemplos

Exemplo #1 Um exemplo da ctype_digit()

<?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";
    }
}
?>

O exemplo acima irá imprimir:

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.

Veja Também

  • ctype_alnum() - Verifica se os caracteres são alfanuméricos
  • ctype_xdigit() - Verifica se os caracteres representam um dígito hexadecimal



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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