public function has($key)
    {
        if (isset($this->parameters[$key]) || array_key_exists($key, $this->parameters)) {
            return true;
        }

        return false;
    }
public function has($key)
    {
        if (isset($this->parameters[$key]) || array_key_exists($key, $this->parameters)) {
            return true;
        }

        return false;
    }
public function has ( $ key ) { if ( isset ( $ this -> parameters [ $ key ] ) || array_key_exists ( $ key , $ this -> parameters ) ) { return true ; } return false ; }
Returns whether the key exists or not.

@param string $key name of key to check

@return bool true, if key exists; false otherwise
Returns whether the key exists or not .