php 定义enum

<?php
enum Weekday: string {
    case Monday = 'Monday';
    case Tuesday = 'Tuesday';
    case Wednesday = 'Wednesday';
    case Thursday = 'Thursday';
    case Friday = 'Friday';
    case Saturday = 'Saturday';
    case Sunday = 'Sunday';
}

enum OrderStatus: string {
    case Pending = 'Pending';
    case Paid = 'Paid';
    case Shipped = 'Shipped';
    case Completed = 'Completed';
}

function getDayOfWeekName(Weekday $day): string {
    return $day->name;
}

function getOrderStatusName(OrderStatus $status): string {
    return $status->name;
}

$today = Weekday::Monday;
echo getDayOfWeekName($today); // 输出: Monday

$orderStatus = OrderStatus::Paid;
echo getOrderStatusName($orderStatus); // 输出: Paid
?>

enum Color: int {
    case Red = 1;
    case Green = 2;
    case Blue = 3;
}

function setColor(Color $color): void {
    // 处理颜色设置逻辑
}

$color = Color::Red;
setColor($color); // 正确

$invalidColor = 'Red';
setColor($invalidColor); // 错误，类型不匹配