ctype_cntrl
ctype_graph
Ctype Functions
PHP Manual

# ctype_digit

(PHP 4 >= 4.0.4, PHP 5)

ctype_digit — Check for numeric character(s)

### Description

bool ctype_digit ( string `$text` )

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

### Parameters

`text`

  The tested string.

### Return Values

Returns `TRUE` if every character in the string `text` is a decimal digit, `FALSE` otherwise.

### Changelog

Version | Description
--- | ---
5.1.0 | Before PHP 5.1.0, this function returned `TRUE` when `text` was an empty string.

### 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($integer); // false
is_numeric($numeric_string); // true
is_numeric($integer); // true
?>`

### Notes

> Note: This function require a string to be useful, so for example passing in an integer will always return `FALSE`. However, also note that HTML Forms will result in numeric strings and not integers. See also the types section of the manual.

### See Also

- ctype_alnum() - Check for alphanumeric character(s)
- ctype_xdigit() - Check for character(s) representing a hexadecimal digit
- is_numeric() - Finds whether a variable is a number or a numeric string
- is_int() - Find whether the type of a variable is integer
- is_string() - Find whether the type of a variable is string

ctype_cntrl
ctype_graph
Ctype Functions
PHP Manual