How to Produce Good and Resource-friendly PHP Code

PHP is the pop web-development language of the day, easy to learn and apply, with thousands of free resources available all across the web. However, the ease with which the basics of the language are picked up is a recipe for many coding disasters. What are good coding practices, and where are the common pitfalls?

This article outlines some of the facets of good and resource-friendly coding in PHP. The following, drawing from my six years with PHP and interactions with fellow coders, should also be helpful to developers who work with other languages, and even make general sense to the non-developer audience who may be looking at hiring a coder.

Does raw performance translate into goodness in coding? Well, resource-friendly coding is one thing. While it certainly is an important aspect of good coding, it alone does not good coding make. We'll move ahead and cover both areas in brief. First, let's get the general goodness covered.

On good coding practice

Think over the structure of the application and the elements required before you start coding to ensure the effective use of your time and code. Even, make dummy files for each element before you start filling them in.

Code with security in mind. In applications that take user input, which is most of the lot, ensure that the input cannot be used to exploit the code in unintended ways. Go over your own script and try to exploit it yourself.

Wherever possible, create replicable patterns instead of hard-coding everything. Use functions for recurring processing events, use arrays and loops for output with recurring patterns. That'll make the changing and the extending of the code much more pleasant an experience in the future. Even, go object-oriented and use classes.

In general, think of the code as something you need to possibly extend in the future, and keep the ends open so as to not have to re-code aspects from a scratch to accommodate future features.

Keep your code well formatted and commented to keep it readable both for yourself and for others. Commenting the code helps you in the long run, as a time will eventually come when you'll need to return to that old chunk of code, wiped off your mind ages ago. And of all things that affect performance, a bit of space here and there isn't one!

The above are a few bits on being a good citizen in the world of PHP development.

On being resource-friendly

While by no means an exhaustive outline, the following are some things that generally need attention, noted in an order of importance in my code lair.

Avoid superfluous MySQL database-queries. Use JOIN to fetch data from across tables into a single query. You can do either one well thought-out query or five queries, and that makes all the difference.

Especially when long TEXT database fields are involved, for example in blog or news entries, don't select * if you need to just show summaries such as headlines - select only the few fields you really need.

If you have an application that takes advantage of dozens of PHP files via include, don't include every file all over the place - use conditional statements to assess which includes are required, thereby skipping both the disk access time and the memory overhead caused by a host of functions, classes and variables.

Don't do the same things many times over. Cache elements that don't change. For example, if you need to loop over an array to output something in several places, just run the array once and store the output into a variable you output every time the desired output is required.

As ought to be obvious from the above, the mere knowing of language constructs doth not a good coder make. Aside memorizing the manual - and whoever in the world did that! - you need to have the ability to envision the big picture, the entire scope of the application, and have a ton of raw logical brain power to generate efficient structures.Good thinking is the foundation of good coding.