As a general course of study in web development, I recommend learning HTML, CSS, PHP, then JavaScript. It’s very easy to print something to the browser window in the first three languages: in PHP, one typically uses echo, print, printf, or a similar function. You can use echo exactly where you want the information to be shown on the page:

<p><?php echo $var ?>

It’s not always clear how to accomplish the same in JavaScript. The simplest option, and the one most similar to echo, is also the least recommended: document.write

<p>It’s easy to write information to the screen <script>document.write("with JavaScript");</script>

This “inline” JavaScript is inserted exactly where you want the new information to be added. There’s also the closely related document.writeln, which adds a newline character after the insert.

Many developers spend time writing code designed to extract a very specific number of words or characters from a piece of text. This text sample, often drawn from a blog post or comment, is usually displayed with a link that leads the user to read more.  You can see an example on this site in the extracts of articles added to favorites in user profile pages.

Using a thoroughly organized content management schema that divides every article into a lede, nut graph, and body units of text minimizes the need for string manipulation. However, such units are not always available or applicable.

It’s possible to use JavaScript, CSS and server-side languages to create text extracts. For the purposes of this article, I’ll use PHP.

Many developers associate responsive design exclusively with CSS, but the reality is that every web technology has a role to play in optimizing sites for mobile devices. In some cases, there are functionally equivalent features across different languages that allow you to choose the most appropriate tool for a particular set of conditions.

matchMedia is one such feature, allowing CSS3 media queries to be tested directly within JavaScript. The syntax couldn’t be easier: