Here are some of the regular expressions that I frequently use.
Find a blank line
^$
Spaces
[ \t]+
You can use this to break a text string apart into words.
Date
\d{1,2}(\-|\/|\.)\d{1,2}\1\d{4}
This will match anything in the format mm/dd/yyyy, or even dd/mm/yyyy.
If you are looking for information about the MooTools JavaScript framework then your first stop should be the MooTools home page. The site not only allows you to download MooTools, but it is also a great resource for learning how to use MooTools.
Writing regular expressions can sometimes be a real pain, especially if you are not used to them. Rather than trying for yourself to make a regular expression you might want to think about looking for regular expressions that other people have made. Rather than reinventing the wheel to prove you can do something,using free third party regular expressions can save you a lot of time.
Regular expressions are a very useful tool for any programmer wanting to validate input, format strings, change words, reformat data or even split apart a string into an array. However, when you are starting out, writing them it can be hard going, they are not very easy to learn and the only way to really understand them is to practice, practice, practice.
Storing sets of data with a timestamp is common practice, especially if you want to keep a history of the values that have been stored previously. Lets say you wanted to store a piece of information about two variables, each of which can have a history. Here is an example dataset.
The PHP output buffering functions provide a handy way of intercepting the contents of the buffer before it is sent to the browser. The output is whatever is sent to the browser whenever you print something off. PHP allows you to capture this output in a buffer before it is sent to the browser.
Garbage collection is a term for a maintenance function in a class or script that you don't want to run every time the script is run. The main function of the script is to clean up anything that the script has used previously, but is now not important in the general running of the system and can be removed with no ill effects. However, it is important that the garbage collection is not run every time the script is run as it may have a detrimental effect on the speed of the system.
By far the best resource for finding information about PHP and all of the functions available is from the PHP website. Not only can you view the PHP documentation, but you can also download PHP and many of the extensions like the Smarty template system.
Following on from the previous post about the PHP filter functions there are two more filter functions that require some extra explanation. These functions are filter_var_array() and filter_input_array().
They work in much the same way as filter_var() and filter_input() but they accept an array as the input. This enables you to sanitize or validate many different variables at the same time.
The filter functions are part of the PECL library and should come as standard on most PHP 5 installs. If they aren't there then ask your server administrator to install them.
The filter functions where created to avoid developers having to write lots of unmaintainable code in order to check the validity of variables and to sanitize these variables once validated. So rather than using many different functions and regular expressions to tell if a value is a number, a boolean or even a URL, you can just use these filter fucntions.