PHP ctype_alnum() Function Usage and Example

PHP Ctype Function Manual

The ctype_alnum() function checks if the string is composed entirely of letters and/or numbers characters.

Syntax

ctype_alnum(\$text);

Definition and Usage

It checks whether all characters in the provided string are letters and/or numbers.

In the standard C language environment, letters are only [A-Za-z], this function is equivalent to preg_match('/^[a-z0-9]+$/iD ', $text).

Parameter

Return Value

If each character in the text is a letter or number, it returns TRUE, otherwise it returns FALSE.

Online Example

<?php
　　　\$strings = array('hello', 'foo!#$bar');
　　　
　　　foreach (\$strings as \$example) {
　　　　　　if (ctype_alnum(\$example)) {
　　　　　　　　　echo "\$example is composed of letters or numbers.\n";
　　　　　　}else {
　　　　　　　　　echo "\$example is not entirely letters or numbers.\n";
　　　　　　}
　　　}
?>

Output Result:

hello is composed of letters or numbers.
foo!#$bar is not entirely letters or numbers.

PHP Ctype Function Manual