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10 Advanced PHP Tips To Improve Your Programming

Update (25.03.2009): this article contains some factual errors. Please read the rebuttal of this article1 instead of this article.

PHP programming has climbed rapidly since its humble beginnings2 in 1995. Since then, PHP has become the most popular programming language for Web applications. Many popular websites are powered by PHP, and an overwhelming majority of scripts and Web projects are built with the popular language.

Because of PHP’s huge popularity, it has become almost impossible for Web developers not to have at least a working knowledge of PHP. This tutorial is aimed at people who are just past the beginning stages of learning PHP and are ready to roll up their sleeves and get their hands dirty with the language. Listed below are 10 excellent techniques that PHP developers should learn and use every time they program. These tips will speed up proficiency and make the code much more responsive, cleaner and more optimized for performance.

1. Use an SQL Injection Cheat Sheet Link

Sql Injection3
A list of common SQL injections.

SQL injection4 is a nasty thing. An SQL injection is a security exploit that allows a hacker to dive into your database using a vulnerability in your code. While this article isn’t about MySQL, many PHP programs use MySQL databases with PHP, so knowing what to avoid is handy if you want to write secure code.

Furruh Mavituna has a very nifty SQL injection cheat sheet5 that has a section on vulnerabilities with PHP and MySQL. If you can avoid the practices the cheat sheet identifies, your code will be much less prone to scripting attacks.

2. Know the Difference Between Comparison Operators Link

Equality Operators6
PHP’s list of comparison operators.

Comparison operators7 are a huge part of PHP, and some programmers may not be as well-versed in their differences as they ought. In fact, an article at I/O reader states that many PHP developers can’t tell the differences right away between comparison operators. Tsk tsk.

These are extremely useful and most PHPers can’t tell the difference between == and ===. Essentially, == looks for equality, and by that PHP will generally try to coerce data into similar formats, eg: 1 == ‘1′ (true), whereas === looks for identity: 1 === ‘1′ (false). The usefulness of these operators should be immediately recognized for common functions such as strpos(). Since zero in PHP is analogous to FALSE it means that without this operator there would be no way to tell from the result of strpos() if something is at the beginning of a string or if strpos() failed to find anything. Obviously this has many applications elsewhere where returning zero is not equivalent to FALSE.

Just to be clear, == looks for equality, and === looks for identity. You can see a list of the comparison operators8 on the website.

3. Shortcut the else Link

It should be noted that tips 3 and 4 both might make the code slightly less readable. The emphasis for these tips is on speed and performance. If you’d rather not sacrifice readability, then you might want to skip them.

Anything that can be done to make the code simpler and smaller is usually a good practice. One such tip is to take the middleman out of else statements9, so to speak. Christian Montoya has an excellent example10 of conserving characters with shorter else statements.

Usual else statement:

if( this condition )
$x = 5;
$x = 10;

If the $x is going to be 10 by default, just start with 10. No need to bother typing the else at all.

$x = 10;
if( this condition )
$x = 5;

While it may not seem like a huge difference in the space saved in the code, if there are a lot of else statements in your programming, it will definitely add up.

4. Drop those Brackets Link

Drop Brackets11
Dropping brackets saves space and time in your code.

Much like using shortcuts when writing else functions, you can also save some characters in the code by dropping the brackets in a single expression following a control structure. has a handy example12 showcasing a bracket-less structure.

if ($gollum == 'halfling') {
$height --;

This is the same as:

if ($gollum == 'halfling') $height --;

You can even use multiple instances:

if ($gollum == 'halfling') $height --;
else $height ++; 
if ($frodo != 'dead')
echo 'Gosh darnit, roll again Sauron';
foreach ($kill as $count)
echo 'Legolas strikes again, that makes' . $count . 'for me!';

5. Favour str_replace() over ereg_replace() and preg_replace() Link

Str Replace
Speed tests show that str_replace() is 61% faster.

In terms of efficiency, str_replace()13 is much more efficient than regular expressions at replacing strings. In fact, according to Making the Web, str_replace() is 61% more efficient than regular expressions like ereg_replace()14 and preg_replace()15.

If you’re using regular expressions, then ereg_replace() and preg_replace() will be much faster than str_replace().

6. Use Ternary Operators Link

Instead of using an if/else statement altogether, consider using a ternary operator16. PHP Value gives an excellent example of what a ternary operator looks like.

//PHP COde Example usage for: Ternary Operator
$todo = (empty($_POST[’todo’])) ? ‘default’ : $_POST[’todo’]; 
// The above is identical to this if/else statement
if (empty($_POST[’todo’])) {
$action = ‘default’;
} else {
$action = $_POST[’todo’];

The ternary operator frees up line space and makes your code less cluttered, making it easier to scan. Take care not to use more than one ternary operator in a single statement, as PHP doesn’t always know what to do in those situations.

7. Memcached Link

Memcached is an excellent database caching system to use with PHP.

While there are tons of caching options out there, Memcached18 keeps topping the list as the most efficient for database caching. It’s not the easiest caching system to implement, but if you’re going to build a website in PHP that uses a database, Memcached can certainly speed it up. The caching structure for Memcached was first built for the PHP-based blogging website LiveJournal. has an excellent tutorial on installing and using memcached19 with your PHP projects.

8. Use a Framework Link


CakePHP is one of the top PHP frameworks.

You may not be able to use a PHP framework for every project you create, but frameworks like CakePHP21, Zend22, Symfony23 and CodeIgniter24 can greatly decrease the time spent developing a website. A Web framework is software that bundles with commonly needed functionality that can help speed up development. Frameworks help eliminate some of the overhead in developing Web applications and Web services.

If you can use a framework to take care of the repetitive tasks in programming a website, you’ll develop at a much faster rate. The less you have to code, the less you’ll have to debug and test.

9. Use the Suppression Operator Correctly Link

The error suppression operator (or, in the PHP manual, the “error control operator25“) is the @ symbol. When placed in front of an expression in PHP, it simply tells any errors that were generated from that expression to now show up. This variable is quite handy if you’re not sure of a value and don’t want the script to throw out errors when run.

However, programmers often use the error suppression operator incorrectly. The @ operator is rather slow and can be costly if you need to write code with performance in mind.

Michel Fortin has some excellent examples26 on how to sidestep the @ operator with alternative methods. Here’s an example of how he used isset to replace the error suppression operator:

if (isset($albus))  $albert = $albus;
else                $albert = NULL;

is equivalent to:

$albert = @$albus;

But while this second form is good syntax, it runs about two times slower. A better solution is to assign the variable by reference, which will not trigger any notice, like this:

$albert =& $albus;

It’s important to note that these changes can have some accidental side effects and should be used only in performance-critical areas and places that aren’t going to be affected.

10. Use isset instead of strlen Link

Switching isset for strlen makes calls about five times faster.

If you’re going to be checking the length of a string, use isset instead of strlen. By using isset, your calls will be about five times quicker. It should also be noted that by using isset, your call will still be valid if the variable doesn’t exist. The D-talk has an example of how to swap out isset for strlen:

A while ago I had a discussion about the optimal way to determine a string length in PHP. The obvious way is to use strlen().

However to check the length of a minimal requirement it’s actually not that optimal to use strlen. The following is actually much faster (roughly 5 times)

It’s a small change but, like all the tips we’ve covered today, adds up to quicker, leaner code.


Footnotes Link

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Glen Stansberry is the editor at Web Jackalope, a blog about creative Web development.

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  3. 3

    nice article

  4. 4

    these are great although not using common brackets and universal indentation will just make it harder to read code

  5. 5

    Dropping the brackets is a great way to make your code less readable. It’s a stupid tip.

  6. 6

    I don’t really agree with dropping brackets left and right. I’ve always been taught it’s good practice to use them, because you can easily see where the conditions/loops are when scanning your code. Same with the use ternary operators and other shorthands – people overuse them and it makes it nearly impossible to debug their code later down the road.

    Let me ask, has anybody really noticed a difference in speed/load with:
    $var = "my name is bob";
    compared to
    $var = 'my name is bob';
    I’ve never noticed a difference in speed myself, even with pretty high loads.

  7. 7

    I see some bad ideas here. Applying the techniques #4, #6 and #9 will result in lesser readable and maintainable code. A little sidenote concerning performance: It is better to write good code and use caching techniques to increase performance.

  8. 8

    Oh yeah, this article came just in time!! I needed the SQL Injection Cheat Sheet today!

  9. 9

    Some of these tips are micro-optimizations while others are universally useful. I want to add a couple things to the mix:

    – Upgrade your PHP installation to the latest version… currently it’s 5.2+. This way, you can be certain that your server has the latest bugfixes.
    – Use an opcode cacher, like APC, to speed up your execution time. Opcode cachers saved compiled versions of your scripts, so they don’t have to be compiled every time they are run. This will make any PHP site much faster.
    – Use the mysqli class that comes with PHP 5 instead of the old mysql. This allows you to do object-based queries with bound parameters, which prevents SQL injection by ensuring that every parameter will be checked and forced to be an integer or a string, and will then be contained within the query, even if they have quotation marks injected.

    But the most important tip I can share is, always be learning!

  10. 10

    I don’t see a speed difference when choosing or . I would recommand using . Because in notepad++, the $var is good colored !

    Nice post.

  11. 11

    Tips 3 and 4 are really bad. It’s much better to use certain coding styles.

  12. 12

    This is just blatant irresponsible use of the word “advanced”

    How the heck is knowing the difference between == and ===, advanced?
    or that str_replace is faster than regex?

    You learn this crap in your first pass through the manual.

    I eagerly clicked to read this article because i thought to myself, ‘ok, something new has been found out’ and all i found was this marketed garbage.

    shame on you.

  13. 13

    I like this article, it points out a regular problem : performances vs legibility.

    Personally, I always drop the brackets when I can (meaning : a short test and a single short consequent). I know this is considered to be less readable, but if it is the case, it’s probably that this is the consequent (or the test) that isn’t readable enough, not the conditional form itself (providing you use a good indentation).

    On the other hand, #10 seems to be definitively tricky when you read it.

    @matt : I agree with you, but here, it is to use caching techniques *and* to write fast code. The audience must be extreme speed requirement applications.

  14. 14

    You PHP people are funny

    1. If you don’t know the difference between comparison operators you shouldn’t be coding.

    2. Use brackets, please use them, they make the code easier to read and it’s good practice.

    3. If your code is open to SQL Injection then you don’t know how to code. I could understand people having this problem ten years ago.

    4. Shortcut else? Just lazy mans code.

    Tip of the day! Use ASP.NET/C#.NET

    C# is an ISO standard, I don’t think PHP is?

  15. 15

    Giovanni Battista Lenoci

    November 18, 2008 6:47 am

    I don’t agree with tip 4, dropping brackets make code less readable.
    I use sometimes ternary operators, but also this tecnique make code less readable.
    I’ve never tested a code with brackets an without brackets, but I don’t think that the results are so different.

    Reguarding tip #9, I don’t know what was in the writer mind, but without an explanation this could lead to unwanted results:

    $a = 5;
    $b = $a;
    $a = 10;
    echo $a."-".$b; // 10 - 5
    $a = 5;
    $b =& $a;
    $a = 10;
    echo $a."-".$b; // 10 - 10

    For other tips, some are ok, some are banal.
    I suggest to change the article title in to 10 Advanced PHP Tips To Improve Your Programming (not so much)

  16. 16

    troll ?

  17. 17

    Great but you should rename the post to:

    “6 adavanced tips to mess up your code!”

  18. 18

    Tip 4 is just bad advice, it goes against most “best practices”. What if you add one more line in the future? You’ll forget the brackets and your code doesn’t work as it should!

    Tip 9 is just as bad. It even goes against Zend recommendations. In the Zend recommendations it is explicitly stated that you should never assign by reference unless you really need it. Also the other side-effects this might cause is another reason to not use assign-by-reference just to avoid a suppression operator.

    Tip 6 is debatable. Some guidelines ask to not use ternary operators to improve readability. If I’m not mistaken that is one of the reasons it’s not in Python.

    The author of this article is one PHP Coder I’d rather not hire and it’s really a shame that this article has appeared on SmashingMagazine.

  19. 19

    Agree with the previous posters, there are some dreadful tips here. Shorthand else and dropping braces do nothing but decrease the legibility of your code.

    Shorter code in terms of short cuts like these are not a sign of good code. “Anything that can be done to make the code simpler and smaller is usually a good practice” is a terrible generalisation. Far better practices to adhere to are following OO programming principles that encourage reusable, modular code.

    Furthermore, the article is contradictory – it encourages you to use a framework, but those frameworks have coding standards that automatically invalidate these two rules! For example, the Zend framework states: “PHP allows statements to be written without braces in some circumstances. This coding standard makes no differentiation- all “if”, “elseif” or “else” statements must use braces.”

    This article is a good idea, but has been poorly thought out.

  20. 20

    I don’t agree with the 4th tip.


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