PHP代码重构与设计改善重构是改善既有代码设计而不改变外部行为的过程。今天说说PHP代码重构的常见模式和技巧。提取方法是最常用的重构手法。php// 重构前class OrderProcessor{public function process(array $order): array{$total 0;foreach ($order[items] as $item) {$total $item[price] * $item[quantity];}if ($order[coupon] ! null) {$total $total * 0.9;}if ($total 100) {$total $total * 0.95;}$order[total] $total;$log date(Y-m-d H:i:s) . 订单金额: $total\n;file_put_contents(/tmp/orders.log, $log, FILE_APPEND);return $order;}}// 重构后class OrderProcessorRefactored{public function process(array $order): array{$total $this-calculateTotal($order);$order[total] $total;$this-logProcessing($order);return $order;}private function calculateTotal(array $order): float{$total $this-calculateItemsTotal($order[items]);$total $this-applyCoupon($total, $order[coupon] ?? null);$total $this-applyBulkDiscount($total);return $total;}private function calculateItemsTotal(array $items): float{$total 0;foreach ($items as $item) {$total $item[price] * $item[quantity];}return $total;}private function applyCoupon(float $total, ?string $coupon): float{return $coupon ! null ? $total * 0.9 : $total;}private function applyBulkDiscount(float $total): float{return $total 100 ? $total * 0.95 : $total;}private function logProcessing(array $order): void{$log date(Y-m-d H:i:s) . 订单金额: {$order[total]}\n;file_put_contents(/tmp/orders.log, $log, FILE_APPEND);}}?替换条件逻辑为多态。phpinterface FeeStrategy{public function calculate(float $amount): float;}class NormalFee implements FeeStrategy{public function calculate(float $amount): float { return $amount * 0.01; }}class VipFee implements FeeStrategy{public function calculate(float $amount): float { return $amount * 0.005; }}class PremiumFee implements FeeStrategy{public function calculate(float $amount): float { return 0; }}class FeeCalculator{public function __construct(private FeeStrategy $strategy) {}public function calculate(float $amount): float{return $this-strategy-calculate($amount);}}?引入参数对象。php// 重构前function searchUsers(string $name, string $email, int $age, string $status, int $page, int $perPage): array{return [];}// 重构后class SearchCriteria{public function __construct(public ?string $name null,public ?string $email null,public ?int $age null,public ?string $status null,public int $page 1,public int $perPage 20,) {}}function searchUsers(SearchCriteria $criteria): array{return [];}$criteria new SearchCriteria(name: 张三, status: active);searchUsers($criteria);?分解复杂条件。php// 重构前if ($user[status] active $user[balance] 0 !$user[frozen] $user[verified]) {// 处理}// 重构后function canProcessPayment(array $user): bool{return $user[status] active $user[balance] 0 !$user[frozen] $user[verified];}if (canProcessPayment($user)) {// 处理}?重构的核心原则是每次只改一点保持测试通过。提取方法、替换条件为多态、引入参数对象这些是常用的重构手法。好的代码不是一次写出来的是不断重构打磨出来的。