public function has($key)
    {
        if (\array_key_exists($key, $this->data)) {
            return true;
        }

        if (null === $this->parent) {
            return false;
        }

        return $this->parent->has($key);
    }
public function has($key)
    {
        if (\array_key_exists($key, $this->data)) {
            return true;
        }

        if (null === $this->parent) {
            return false;
        }

        return $this->parent->has($key);
    }
public function has ( $ key ) { if ( \ array_key_exists ( $ key , $ this -> data ) ) { return true ; } if ( null === $ this -> parent ) { return false ; } return $ this -> parent -> has ( $ key ) ; }
Tests if a data is visible from current scope.

@param string $key

@return bool
Tests if a data is visible from current scope .