PHP 列挙型の管理と設計

const YES = '是'; const NO = '否';

class BoolEnum { const YES = '是'; const NO = '否'; }

BoolEnum::YES(); // 是 BoolEnum::NO(); // 否

BoolEnum::toArray(); // ['Yes' => '是', 'No' => '否']

abstract class Enum { // 获取所有枚举类型 public static function toArray(){ // 通过反射获取常量 $reflection = new \ReflectionClass(static::class); $contants = $reflection->getConstants(); // 返回对应的常量 return $contants; } // 动态调用属性 public static function __callStatic($name, $arguments) { $arr = static::toArray(); if(isset($arr[$name])){ return $arr[$name]; } throw new \BadMethodCallException("找不到对应的枚举值 {$name}"); } } class BoolEnum extends Enum { const YES = '是'; const NO = '否'; }

abstract class Enum { protected static $cache = []; public static function toArray(){ $class = static::class; // 第一次获取，就通过反射来获取 if(! isset(static::$cache[$class])){ $reflection = new \ReflectionClass(static::class); static::$cache[$class] = $reflection->getConstants(); } return static::$cache[$class]; } }

$yes = new BoolEnum("是"); echo $yes; // "是"

abstract Enum { protected $value; public function __construct($value) { if ($value instanceof static) { $value = $value->getValue(); } if(! $this->isValid($value)){ throw new \UnexpectedValueException("$value 不属于该枚举值" . static::class); } $this->value = $value; } // 获取实例对应的键 public function getKey(){ return array_search($this->value, static::toArray(), true); } // 获取实例对应的值 public function getValue() { return $this->value; } // 允许字符串形式输出 public function __toString() { return $this->value; } // 验证值是否合法 public function isValid($value) { $arr = static::toArray(); return in_array($value, $arr, true); } // 验证键是否合法 public function isValidKey($key) { $arr = static::toArray(); return array_key_exists($key, $arr); } }

$user->banned = '非法值'; // 可能不会报错 $yes = new BoolEnum("非法值"); // 将会抛出异常 $user->banned = $yes;

function setUserStatus(BoolEnum $boolEnum){ $user->banned = $boolEnum; }