cancelReason = ""; $this->cancelAmount = 0; $this->refundReceiveAccount = null; $this->taxFreeAmount = 0; } public function toArray(): array { $result = [ 'cancelReason' => $this->cancelReason ]; if($this->cancelAmount) { $result['cancelAmount'] = $this->cancelAmount; } if($this->refundReceiveAccount) { $result['refundReceiveAccount'] = $this->refundReceiveAccount; } if($this->taxFreeAmount) { $result['taxFreeAmount'] = $this->taxFreeAmount; } return $result; } public function toString(): string|false { return serialize($this->toArray()); } }