ctype_digit

(PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)

ctype_digit — Check for numeric character(s)

Description

ctype_digit(mixed $text): bool

Checks if all of the characters in the provided string, text, are numerical.

Parameters

text

The tested string.

Note:

If an int 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.

Warning

As of PHP 8.1.0, passing a non-string argument is deprecated. In the future, the argument will be interpreted as a string instead of an ASCII codepoint. Depending on the intended behavior, the argument should either be cast to string or an explicit call to chr() should be made.

Return Values

Returns true if every character in the string text is a decimal digit, false otherwise. When called with an empty string the result will always be false.

Examples

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";
}
}
?>

The above example will output:

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
?>

See Also