Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people, just like you, are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
Solved

Check if has only letters, numbers and underscore

Posted on 2006-07-14
2
1,064 Views
Last Modified: 2008-09-09
What is the reg exp syntax for checking if a string has only letters, numbers and underscore in it?

thanks
0
Comment
Question by:blacklord
2 Comments
 
LVL 49

Accepted Solution

by:
Roonaan earned 250 total points
ID: 17106294
if(preg_match('/^\w+$/',$string)) {
  //string not empty and requested chars only
}

-r-
0
 
LVL 40

Expert Comment

by:Richard Quadling
ID: 17106730
NOTE!

A "word" character is any letter or digit or the underscore character, that is, any character which can be part of a Perl "word". The definition of letters and digits is controlled by PCRE's character tables, and may vary if locale-specific matching is taking place. For example, in the "fr" (French) locale, some character codes greater than 128 are used for accented letters, and these are matched by \w.

0

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction HTML checkboxes provide the perfect way for a web developer to receive client input when the client's options might be none, one or many.  But the PHP code for processing the checkboxes can be confusing at first.  What if a checkbox is…
Introduction This article is intended for those who are new to PHP error handling (https://www.experts-exchange.com/articles/11769/And-by-the-way-I-am-New-to-PHP.html).  It addresses one of the most common problems that plague beginning PHP develop…
The viewer will learn how to dynamically set the form action using jQuery.
The viewer will learn how to create and use a small PHP class to apply a watermark to an image. This video shows the viewer the setup for the PHP watermark as well as important coding language. Continue to Part 2 to learn the core code used in creat…

840 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question