gistfile1.txt

class Test
{
  private $obj;
  const MAP = ['testKey' => 'test'];
  
  function __construct() {
    $this->obj = new \stdClass();
    $this->obj->test = "testObject";
  }
  
  public function getConst()
  {
    $name = 'testKey';
    $this->obj->{static::MAP[$name]} = "newObject";
    echo $this->obj->{static::MAP[$name]};
  }
}