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How can I check that a data value is alphanumeric?
By Balu Prasad
How can I check that a data value is alphanumeric?????
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Teacher SiliconIndia replied to Balu Prasad Wednesday, March 17, 2010
Hi Balu,
There are various ways to do this, and people commonly do this with a regular expression of some description.

However if you don't want to get involved with those or find them confusing, as usual with PHP there is a function lurking around to help you achieve your desired result.

You can easily validate specific to the curernt locale setting with the ctype_alpha function, one of the character type functions added to PHP in version 4.3 which works like this:

<?php
$formvalue = "am I alphanumeric or not";
if(ctype_alpha($formvalue)) { echo "Yes I am!"; } else { echo "No I'm not!"; }
?>
In this case printing "No I'm not!" because $formvalue contains spaces.