Common PHP Expressions for Web Development

Expressions provide a short hand way for programmers to update and edit strings on a global basis. For both input and output variables, expressions can ensure formatting is correct, which is particularly useful for forms, structured data and special output formats.  There are a wide variety of regular expressions in PHP 5 which come in useful for ensuring proper output and formatting within your code. If you’re looking to ensure proper display and validation of strings within your web application, then it’s important to master various expressions.

There are a variety of concrete applications for using expressions within your code so you can properly format the content.  One common example is protecting users by making sure domain names are properly formatted – having the proper structure can ensure they don’t get 301 or 404 errors, especially if you have users submitting links, sites or resources through comments. You can accomplish this using preg_match which ensures strings meet a certain set of parameters:

$site = "http://exampledomain.com/";

if (preg_match('/^(http)://([A-Z0-9][A-Z0-9_-]
    *(?:.[A-Z0-9][A-Z0-9_-]*)+):?(d+)?/?/i', $site))
{
   echo "Valid domain – thanks for your submission.";
}
else
{
   echo "Invalid domain – please check formatting and re-enter.";
}

According to this code, the script identifies whether a certain URL meets proper formatting for characters, hyphens, spacing and prefix. If we wanted to we could also allow only certain domain extensions (com, net, org, etc) or we could also allow https (secure websites.) You can modify the code according to the specific parameters relevant to your site.

When it comes to search optimization on your PHP site, one major area to focus on is keyword placement. Users who land on your site want to ensure the content is relevant to their search, and you can to encourage them to stay on your site. One way to accomplish this goal is to use PHP to highlight the relevant text within your page. Since analytics records visit time and bounce rates, this data can help improve user engagement as well as (potentially) search rankings for certain keywords. When users identify their search queries directly on the site they are much more likely to remain on the site. Suppose you wanted to highlight the query in yellow and bold it on the page – you would just have to use the preg)replace function which is used to update the formatting on specific contents within your site. You can accomplish this by implementing the following code on your site:

$query = "Example text for your website with search query.";

$query = preg_replace("/b(regex)b/i",
'<span style="background:#FAF8CC">1</span>', $query);

echo $query;

There are a wide variety of options you can also use ranging from adding quotes to specific characters to building lists based upon input. When it comes to modifying your site based upon user input or validating certain inputs, regular expressions serve a valuable purpose. PHP is a powerful language for delivering, modifying and updating content on your site in a dynamic manner, and regular expressions can help ensure the formatting of your content matches your goals. Mastering regular expressions should be a core goal for developers as well as those working on search optimization.

Links

• Online Regular Expression Builder
• Top 10 PHP Hosting Reviews