Better to use an Object or a Static Function in PHP?

Question

I am trying to learn OO and classes and all that good stuff in PHP, I am finally learning the sytax good enough to use it some and I am curious if there is any benefit of starting a new object instead of just using static methods...let me show some code for what I mean...

<?PHP
test class
{
    public function cool()
    {
         retunr true;

    }
}

//Then calling it like this
$test = new test();
$test->cool();
?>

OR

<?PHP
test class
{
    public static function cool()
    {
         retunr true;

    }
}

//Then calling it like this
test::cool();

?>

I realize this is the most basic example imaginable and the answer probably depends on the situation but maybe you can help me understand a little better

Answer 1

Think of classes like 'blueprints' to an object. you want to use the static method when it is a general function that could apply to anywhere, and use methods when you want to reference that specific object.

Answer 2

For your example, it is better to use a static function, but most situations will not be so simple. A good rule of thumb to start with is that if a method doesn't use the $this variable, then it should be made static.

Answer 3

Here is an article that discusses differences in performance between these concepts: http://www.webhostingtalk.com/showthread.php?t=538076.

Basically there isn't any major difference in performance, so then the choice is made based on your design.

If you are going to create an object several times, then obviously a class makes sense.

If you are creating a utility function that isn't tied to a particular object, then create a static function.