Darren set up Online Selling in January 2009 providing website design and eCommerce websites.

PHP will be celebrating its 15th birthday this year, and now is a great time to look back and wonder at how it’s managed to become such an integral part of internet design and application during that time.

It has become one of the first choice languages of web application developers, the go-to language if your website needs something more than what HTML can give you. Over 20 million domains have PHP installed, and it is considered the most popular Apache HTTP Server module by far. Some of the most famous examples of PHP at work are Facebook, Wikipedia, Yahoo!, Digg, Joomla, WordPress, YouTube, and more. PHP has become part of the internet.

For the anniversary of PHP, I decided a “5 Useful Tips” list was in order, to help you use PHP to its full potential (and to avoid some of the problems inherent in the language!). I hope you find these useful.

1. PHP memory allocation

PHP scripts have a memory allocation attached to them by the server. To stop a PHP script taking up too much processing power, usually an arbitrary Mb usage is allocated. Sometimes this is a hinderance to web developers, so to increase the amount of memory allowed, enter the following line into the php.ini file on the root of your website. If the php.ini doesn’t exist, you can simply create it. You can increase this number if you still need more memory, but you may find an upper limit set by your host.

memory_limit=16M

2. PHP include functions

PHP can be used to great effect on websites which don’t involve any database interaction. By using the PHP include function, you can include another .php file anywhere in the current file. This can be extremely useful to include, for examples, headers, or footers, or a left menu that stays fixed. Instead of having to make changes to each file in the future, you can change the one PHP included into all the others. The syntax for including a file is as follows:

<?php include ('directory/file.php'); ?>

3. Setting variables in PHP

Another really useful PHP tip is to create variables, which can be a huge time saver later on down the line. Do you have to regularly enter a phone number or email address? By storing bits of information into variables, you can change the information and once and have it propegate site-wide instantly. No more Find and Replace, we say. To store a variable, use the following code:

$variable_name = 'variable_result';

And to call the variable, use:

<?php echo $variable_name; ?>

4. Using if statements in PHP

Using if statements in PHP can be incredibly useful for only showing information you really want to. The potential that an if statement can give you is huge, and the syntax is incredibly easy to use. For example, if the variable telephone1 is defined, then show it:

<?php if
("$telephone1" != "") {
	echo ("$telephone1");
} ?>

5. Difference between single and double quotes

In PHP there is a difference when using either single or double quotes, either ‘ or “. If you use double quotes ” then you are telling the code to check for a variable. If you are using single quotes ‘ then you are telling it to print whatever is between them. This might seem a bit trivial, but if you use the double quotes instead of the single quotes, it will still output correctly, but you will be wasting processer time.

So that’s it, 5 useful and hopefully time-saving tips for you. I’d love to hear any feedback you have on these solutions, whether they worked for you, or whether you have another useful tip to share with others.

You can view more of Darren’s work at Online Selling where he provides website design and eCommerce websites.