For this example, imagine you had this desire to write your own unit tests. Now, lets say you want to have the ability to intergrate test functions in the same class as the actual functions themselves. To do this, we need to somehow mark the functions as a test function. Of course, with our new found love of attributes, we find that it is suprisingly easy to simply add a single attribute to the funtion to declare it as a test function:
/** @TestFunction */
public function testValidation() { ... }
@TestFunction
public function testValidation() { ... }
[TestFunction]
public function testValidation() { ... }
Once the TestFunction has been defined, your test code can interrogate
the attributes of each function in a class, and only run the functions wich have
that attribute present. The way that you interrgate for attributes depends on the
language and environment being used, but the general concept is the same everywhere.