OOP PHP - correct way to use a parent obj instance from children and other classes -

i have code:

class myobj {     private $var1;     private $var2;     private $var3;      function __construct() {         $this->var1 = false;         $this->var2 = false;         $this->var3 = 0;     }      function getvar1() {         return $this->var1;     }     function getvar2() {         return $this->var2;     }     function getvar3() {         return $this->var3;     }      function setvar1($var1) {         $this->var1 = $var1;     }     function setvar2($var2) {         $this->var2 = $var2;     }     function setvar3($var3) {         $this->var3 = $var3;     } }  class aa {     // ... }  class extends aa {     public $myobj;     public function __construct() {         $this->myobj = new myobj();     }     public function getmyobj() {         return $this->myobj;     } }  class b extends {     public function __construct() {         parent::__construct();         $this->fun1();     }     private function fun1() {         $this->myobj->setvar1(true);     } } class c extends {     public function __construct() {         parent::__construct();         $this->fun2();     }     private function fun2() {         $this->myobj->setvar2(true);     } }  class otherclass extends aa {     public function __construct() {         $b = new b();         $c = new c();         $c->getmyobj()->setvar3(5);          var_dump ( $c->getmyobj()->getvar1() ); // false         var_dump ( $c->getmyobj()->getvar2() ); // true         var_dump ( $c->getmyobj()->getvar3() ); // 5          echo "<br/><br/>";          var_dump ( $b->getmyobj()->getvar1() ); // null          var_dump ( $b->getmyobj()->getvar2() ); // false          var_dump ( $b->getmyobj()->getvar3() ); // 0     } }  new otherclass(); 

the problem need way access $this->myobj var otherclass in order updates set() functions. i'd expect following result in otherclass constructor:

var_dump ( $c->getmyobj()->getvar1() ); // true var_dump ( $c->getmyobj()->getvar2() ); // true var_dump ( $c->getmyobj()->getvar3() ); // 5 

i don't know either whether using myobj class $c->getmyobj() way track updates various class instances (b, c, otherclass). if not accept tip.

thanks

just solved problem using singleton pattern.

the problem that, calling parent::__construct(); b , c create new instance of $this->myobj ($this->myobj = new myobj();) loosing edits.

i edited code that:

class myobj {      private static $instance;      private $var1;     private $var2;     private $var3;      function __construct() {         $this->var1 = false;         $this->var2 = false;         $this->var3 = 0;     }      function getvar1() {         return $this->var1;     }     function getvar2() {         return $this->var2;     }     function getvar3() {         return $this->var3;     }      function setvar1($var1) {         $this->var1 = $var1;     }     function setvar2($var2) {         $this->var2 = $var2;     }     function setvar3($var3) {         $this->var3 = $var3;     }      public static function getinstance(){         if( !isset( self::$instance ) ){             self::$instance = new myobj();         }         return self::$instance;     }  }  class aa {  }     class extends aa {     public function __construct() {      } }  class b extends {     public function __construct() {         parent::__construct();         $this->fun1();     }     private function fun1() {         $myobj = myobj::getinstance();         $myobj->setvar1(true);     } } class c extends {     public function __construct() {         parent::__construct();         $this->fun2();     }     private function fun2() {         $myobj = myobj::getinstance();         $myobj->setvar2(true);     } }  class otherclass extends aa {     public function __construct() {         $myobj = myobj::getinstance();         $b = new b();         $c = new c();         $myobj->setvar3(5);          var_dump ( $myobj->getvar1() ); // true         var_dump ( $myobj->getvar2() ); // true         var_dump ( $myobj->getvar3() ); // 5     } }  new otherclass();