Learning PHP – Things to Remember

As I continue on with Drupal I’m also beginning to digest PHP. I’ve worked with just about every programming language there is: Java, C, C++, Cold Fusion, Python, Perl, and even Fortran. I find scripting languages an excellent choice for web programming. However there is always a few tricks that you need to know – and these are easy to forget. I’m going to use this post as a place to “remember” these. Once I get enough I’m going to turn this into a page. If you have any tricks you’d like to contribute, just post a comment.

Things To Remember with PHP 5:

• Use isset() to test if a variable has a value.
• variable names are case sensitive; functions and stuff are not
• PHP is cool; Perl is not {just checking to see if you are paying attention :-)}
• When working with numbers watch out for wacky type conversion issues between types. Integers over about 2 billion are converted over to floats automatically. Booleans that are true convert to 1 but false converts to an empty string. Use type casting.
• Variable variables are interesting (kind of like c pointers). As with c pointers, if you don’t know what you’re doing then do not use them.
• Superglobal Arrays are incredibly useful, but also dangerous and a source of too much pasta in your programming diet.
• Objects are always passed by reference.
• Function arguments are pass by value with “$arg1” notation; to pass by reference use “&$arg1” notation.
• Use PDO for database connectivity.
• The foreach loop is powerful for iterating over arrays
• There are a number of very powerful array functions that are especially suited to database applications.
• Understand how things work before you use them not after – for example if you use XAMPP make sure you know the differences between their PHP config and the default from php.net because they are not the same.
• The ending “%>” is not required anymore…
• Control your extensions in php.ini and don’t have more than you really need.
• Regular Expressions are a key to high performance PHP applications.

Finally – these are fantastic PHP links to use for learning:

• http://hudzilla.org/phpwiki/
  
• 3-tier Development with PHP
• PHP Manual
• PHP Function Quick Reference
• PDO MySQL Introduction ; PDO Tutorial
• Using PDO Objects in PHP 5
• Alejandro Gervasio has a ton of short and well done articles on DevShed

I’ll update this as I continue to learn more about PHP. My main focus will be on developing database applications and looking at application architectures.