ScotlandPHP

ctype_digit

(PHP 4 >= 4.0.4, PHP 5, PHP 7)

ctype_digitSınama, rakamlar için yapılır

Açıklama

bool ctype_digit ( string $metin )

Belirtilen metin içindeki karakterlerin hepsi rakamlardan oluşuyorsa TRUE döner.

Değiştirgeler

metin

Sınanacak dizge.

Dönen Değerler

Belirtilen metin içindeki karakterlerin hepsi birer rakam ise TRUE, değilse FALSE döner.

Sürüm Bilgisi

Sürüm: Açıklama
5.1.0 PHP 5.1.0 öncesinde, metin boş bir dizge bile olsa bu işlev TRUE döndürürdü.

Örnekler

Örnek 1 - ctype_digit() örneği

<?php
$dizgeler 
= array('1820.20''10002''wsl!12');
foreach (
$dizgeler as $dizge) {
    if (
ctype_digit($dizge)) {
        echo 
"$dizge tamamen rakamlardan oluşuyor.\n";
    } else {
        echo 
"$dizge tamamen rakamlardan oluşmuyor.\n";
    }
}
?>

Yukarıdaki örneğin çıktısı:

1820.20 tamamen rakamlardan oluşmuyor.
10002 tamamen rakamlardan oluşuyor.
wsl!12 tamamen rakamlardan oluşmuyor.

Örnek 2 - ctype_digit() (dizgelerle tamsayıları karşılaştırma) örneği

<?php

$numeric_string 
'42';
$integer        42;

ctype_digit($numeric_string);  // true
ctype_digit($integer);         // false

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

Notlar

Bilginize:

Bu işlevin işe yaraması için değiştirgesi bir dizge olmalıdır. Bir tamsayı verilirse daima FALSE döndürür. Bununla birlikte HTML formlarının sayısal dizge döndürdüklerini, tamsayı döndürmediklerini hatırlamakta fayda var. Ayrıca, veri türleri bölümüne de bakınız.

Ayrıca Bakınız

  • ctype_alnum() - Sınama, abecesayısal karakterler için yapılır
  • ctype_xdigit() - Sınama, onaltılık rakamlar için yapılır
  • is_numeric() - Değişken bir sayı veya bir sayısal dizge mi diye bakar
  • is_int() - Değişken bir tamsayı mı diye bakar
  • is_string() - Değişken string türünde mi diye bakar

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User Contributed Notes 12 notes

up
34
info at directwebsolutions dot nl
5 years ago
All basic PHP functions which i tried returned unexpected results. I would just like to check whether some variable only contains numbers. For example: when i spread my script to the public i cannot require users to only use numbers as string or as integer. For those situation i wrote my own function which handles all inconveniences of other functions and which is not depending on regular expressions. Some people strongly believe that regular functions slow down your script.

The reason to write this function:
1. is_numeric() accepts values like: +0123.45e6 (but you would expect it would not)
2. is_int() does not accept HTML form fields (like: 123) because they are treated as strings (like: "123").
3. ctype_digit() excepts all numbers to be strings (like: "123") and does not validate real integers (like: 123).
4. Probably some functions would parse a boolean (like: true or false) as 0 or 1 and validate it in that manner.

My function only accepts numbers regardless whether they are in string or in integer format.
<?php
   
/**
     * Check input for existing only of digits (numbers)
     * @author Tim Boormans <info@directwebsolutions.nl>
     * @param $digit
     * @return bool
     */
   
function is_digit($digit) {
        if(
is_int($digit)) {
            return
true;
        } elseif(
is_string($digit)) {
            return
ctype_digit($digit);
        } else {
           
// booleans, floats and others
           
return false;
        }
    }
?>
up
11
strrev xc tod noxeh ta ellij
7 years ago
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)
up
8
error17191 at gmail dot com
2 years ago
I just wanted to clarify a flaw in the function is_digit() suggested by "info at directwebsolutions dot nl " ..
It returns true in case of negative integers and false in case of strings that contain negative integers .
example:
is_digit(-10); // returns ture
is_digit('-10'); // returns false
up
9
rlerne at gmail dot com
4 years ago
Interesting to note that you must pass a STRING to this function, other values won't be typecasted (I figured it would even though above explicitly says string $text).

I.E.

<?PHP
$val
= 42; //Answer to life
$x = ctype_digit($val);
?>

Will return false, even though, when typecasted to string, it would be true.

<?PHP
$val
= '42';
$x = ctype_digit($val);
?>

Returns True.

Could do this too:

<?PHP
$val
= 42;
$x = ctype_digit((string) $val);
?>

Which will also return true, as it should.
up
12
a_p_leeming at hotmail dot com
8 years ago
Also note that

<?php ctype_digit("-1");   //false ?>
up
6
Peter de Pijd
8 years ago
Note that an empty string is also false:
ctype_digit("") // false
up
2
smicheal2 at gmail dot com
2 years ago
Please note that ctype_digit() will say true for strings such as '00001', which are not technically valid representations of integers, while saying false to strings such as '-1', which are. It's basically a faster version of the regex /^\d+$/. As the name says, it answers the question "does this string contain only digits" literally. It does not answer "is this a valid representation of an integer". If that's what you want, use is_int(filter_var($val, FILTER_VALIDATE_INT)) instead.
up
3
John Saman
7 years ago
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.
up
1
mdsky at web dot de
7 years ago
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.
up
0
Skippy
5 years ago
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;
}
?>
up
0
raul dot 3k at gmail dot com
8 years ago
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
up
-2
zorrosNOSPAMwordsman at NOSPAM dot gmail dot com
1 year ago
If you want to verify whether or not a variable contains only digits, you can type cast it to a string and back to int and see if the result is identical. Like so:

<?php

// (bool) TRUE if only digits, FALSE otherwise
$isOnlyDigits = (string) (int) $input === (string) $input;

?>

I haven't benchmarked it, but I'm guessing it's significantly faster then regular expressions.
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