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Can a class instantiate another class? (PHP)
class first {
    public $a;

    function __construct() {
        $this->a = 'a';
    }
}

class second {
    //$fst = new first();
    //public showfirst() {
        //$firsta = $this->first->a;
    //  echo "Here is first $a: " . $firsta;
    //}
}

class second {
    $fst = new first();
    //public showfirsta() {
    //  $firsta = $this->fst->a;
    //  echo "Here is first $a: " . $firsta;
    //}
}

class First {
    public $a;

    public function __construct() {
        $this->a = 'a';
    }

    public function getA() {
      return $this->a;
    }
}

    class Second {
        protected $fst;
        public function __construct() {
          $this->fst = new First();
        }

        public function showfirst() {
           $firsta = $this->fst->getA();
           echo "Here is first {$firsta}";
        }
    }

    $test = new Second();
    $test->showfirst();

$fst = new first();

public showfirst() {

$firsta = $this->first->a;

echo "Here is first $a: " . $firsta;
}

class second {
    public function showfirst() {
        $fst = new first();
        $firsta = $fst->a;
        echo "Here is first $a: " . $firsta;
    }
}

class second {

    public $fst;

    public function showfirsta() {
    $this->fst = new first();
    $firsta = $this->fst->a;
    echo "Here is first $a: " . $firsta;
    }
}