PHP Ctype

The Ctype extension provided the facility to check the data type of specific characters & strings like that It’s an integer or character, etc.

Example to check whether a given string is pure alphabetic or not

<?php

$strings = array('KjgWZC', 'arf12');

foreach ($strings as $testcase)
{
    if (ctype_alpha($testcase))
    {
        echo "The string $testcase consists of all letters.\n";
    }
    else
    {
        echo "The string $testcase does not consist of all letters.\n";
    }
}

?>

Output

Requirements

None besides functions from the standard C library are always available.

Installation

Beginning with PHP 4.2.0 these functions are enabled by default.

For older versions you have to configure and compile PHP with --enable-ctype.

You can disable ctype support with --disable-ctype.

The Windows version of PHP has built-in support for this extension.

You do not need to load any additional extensions in order to use these functions.

Run-time Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

This extension has no resource types defined.

Predefined Constants

This extension has no constants defined.

Ctype Functions

• ctype_alnum — Check for alphanumeric character(s)

• ctype_alpha — Check for alphabetic character(s)

• ctype_cntrl — Check for control character(s)

• ctype_digit — Check for numeric character(s)

• ctype_graph — Check for any printable character(s) except space

• ctype_lower — Check for lowercase character(s)

• ctype_print — Check for printable character(s)

• ctype_punct — Check for any printable character which is not whitespace or an alphanumeric character

• ctype_space — Check for whitespace character(s)

• ctype_upper — Check for uppercase character(s)

• ctype_xdigit — Check for character(s) representing a hexadecimal digit