PHP function and variable inheritance
<p>Can someone help me understand variable/function inheritance in PHP classes.</p>

<p>My parent class has a function which is used by all the child classes. However each child classes needs to use it's own variable in this function. I want to call the function in the child classes statically. In the example below, the 'world' is displayed, as opposed to the values in the child classes.</p>

<p>Can anyone explain how I can get the function to echo the values in the child classes. Should I be using interfaces? Is this something to do with late static binding (which is unavailable to me due to using a pre 5.3.0 version of PHP)?</p>

<pre><code>class myParent
{
    static $myVar = 'world';
    static function hello()
    {
     echo self::$myVar; 
    }
}

class myFirstChild extends myParent
{
    static $myVar = 'earth';
}

class mySecondChild extends myParent
{
    static $myVar = 'planet';
}

myFirstChild::hello();
mySecondChild::hello();
</code></pre>
