Is PHP allocating memory for each new class that extend the same parent?
<p>I am wondering if PHP will re-use the Parent class. With the following code:</p>

<pre><code>// File parent.php
class Parent {
  $public foo = '';

  public function __construct($args) {
    // ..
  }

  // .. some functions
}

// File child1.php
class Child1 extends Parent {
  public function __construct() {

  }

  // .. Some overridden function
  // .. some extra functions
}

// File child2.php
class Child2 extends Parent {
  public function __construct() {

  }

  // .. some extra functions
}
</code></pre>

<p>Now to use either Child1 or Child2 you need to include the parent.php and childN.php. If I only use Child1 I can imagine they are somehow concatenated into a single being. However if I use Child2 on the same page.. would I get 2 'concatenated' beings, that gobble on memory or is PHP super smart and able to see this and only use/load/whatever the Parent only once.</p>

<p>This example is pretty simplified, but the Parent is pretty big and there are plenty of children!</p>
