PHP is one of those scripting languages with a huge amount of functions, extensions and libraries. As a web developer it is almost impossible to keep track of all those features. This can easily lead to very useful functions drowning in the masses of even more not-so-useful functions.
Here is a short list of five great concepts that we use at Engage that can be very useful and productive when working with PHP projects.
Data filter functions were introduced in PHP 5.2 and are a great replacement for using regular expressions to validate or filter many different types of data such as e-mails, urls, ip-addresses, numbers and more.
Example:
if (filter_var(‘my@email.com’, FILTER_VALIDATE_EMAIL))
{
// E-mail address is valid
}
The filter extension can also be used to sanitize input from e.g. $_POST or $_GET.
Say you only want your users to pick a username with alphanumeric characters, normally you would probably use a regular expression with a function like preg_match. But the problem can actually be simplified a lot by simply using character type checking.
Example:
if (ctype_alnum(‘MyUserN4m3’))
{
// Username contains only alpha numeric characters
}
Ctype also contains functions for matching lowercase characters, whitespace characters and much more.
Be aware that the ctype functions uses the locale, which can be changed with setlocale(…), to match characters, the default C locale will as such only match English characters.
You’re working on a big project and wondering who exactly is calling a specific method. You now have hours of debugging ahead, right? No, not at all.
Using debug_backtrace(…) you can output a backtrace to see what exactly the source is.
The output from calling the function is an array with an item for each function called in the trace, although you should be aware that a lot of information can be returned for each function, so you may want to strip arguments and objects out.
Example:
$trace = debug_backtrace();
foreach ($trace as &$elem) {
unset($elem[‘args’]);
unset($elem[‘object’]);
}
print_r($trace);
This will output simple information about each method call in the backtrace chain.
You may already have heard about the __FILE__ constant, but there are actually many more predefined magic constants, which can be very useful for debugging.
Example:
For a recent project I wanted to print the method name for each function when it was executed, I could simply print the name of the function at the beginning of each function.
But a much faster way was to simply call:
echo __METHOD__ . “n”;
in the beginning of each function I needed to follow.
Check the PHP manual for more useful constants.
PHP has a lot of very useful functions for working with arrays, and knowing them by heart can save you a lot of time and simplify your code a great deal.
Here are some of my favorite array functions
- array_merge($arr1, $arr2, …) – Merges two or more arrays together while keeping keys and values intact
- array_sum($arr) – Calculates the sum of all the values in the array, is for example very useful to calculate average value using array_sum($arr) / count($arr)
- array_intersect($arr1, $arr2, …) – Returns items that are contained in all arrays inputted as arguments, you can also use array_diff($arr1, $arr2, …) to compute the difference between multiple arrays
- array_rand($arr, $num = 1) – Picks a random element in an array, number of elements returned are specified by $num
Do you know other PHP concepts that helps you speed up your everyday productivity? Feel free to share in the comments below.
