title: How to get variable from one class to another?
body: <p>I am a newbie to PHP and have question which writen in Example_02 class.</p>
  
  <pre><code>&lt;?php
  
  class Entity 
  { 
  
      private $components = array(); 
  
      public function add_component(Component $component) 
      { 
          if (in_array($component, $this-&gt;components) == false) 
              $this-&gt;components[] = $component; 
      } 
  
      public function get_component(Component $component) 
      { 
          if (in_array($component, $this-&gt;components) == true) 
              return $this-&gt;components[array_search($component, $this-&gt;components)]; 
      } 
  
  } 
  
  class Component 
  { 
  
  
  
  } 
  
  class Example_01 extends Component 
  { 
  
      public $example_var; 
  
      public function __construct() 
      { 
  
      } 
  
  } 
  
  class Example_02 extends Component 
  { 
  
      public function __construct() 
      { 
          // how to get $example_var from Example_01 class? 
      } 
  
  } 
  
  $ent = new Entity(); 
  $ent-&gt;add_component(new Example_01()); 
  $ent-&gt;add_component(new Example_02()); 
  
  var_dump($ent); 
  
  ?&gt;
  </code></pre>