php 定义枚举

<?php

enum Status: int {
    case Pending = 0;
    case Approved = 1;
    case Rejected = 2;
}

$status = Status::Pending;
echo $status; // 输出: 0

if ($status === Status::Pending) {
    echo "Pending";
}
?>

<?php

enum Color: string {
    case Red = 'red';
    case Green = 'green';
    case Blue = 'blue';
}

$color = Color::Red;
echo $color; // 输出: red

if ($color === Color::Red) {
    echo "Red";
}
?>

<?php

enum Status: int {
    case Pending = 0;
    case Approved = 1;
    case Rejected = 2;
}

$status = Status::Pending;

// 错误示例
if ($status === 0) { // 这里应该使用枚举常量而不是直接使用整数
    echo "Pending";
}

// 正确示例
if ($status === Status::Pending) {
    echo "Pending";
}
?>