php的枚举

<?php
enum OrderStatus: string {
    case Pending = 'pending';
    case Paid = 'paid';
    case Shipped = 'shipped';
    case Completed = 'completed';
}

enum UserRole: string {
    case Admin = 'admin';
    case User = 'user';
    case Guest = 'guest';
}

function processOrder(OrderStatus $status) {
    switch ($status) {
        case OrderStatus::Pending:
            echo "Order is pending payment.";
            break;
        case OrderStatus::Paid:
            echo "Order has been paid.";
            break;
        case OrderStatus::Shipped:
            echo "Order has been shipped.";
            break;
        case OrderStatus::Completed:
            echo "Order has been completed.";
            break;
    }
}

processOrder(OrderStatus::Paid);
?>

// 错误示例
processOrder('invalid_status'); // 会抛出异常

// 正确示例
processOrder(OrderStatus::Pending);

// 错误示例
processOrder(123); // 会抛出异常

// 正确示例
processOrder(OrderStatus::Paid);