如何在PHP中实现类似枚举的功能？
如何在PHP中实现类似枚举的功能？
这个问题已经在下面有答案了:
如何在PHP中使用类似Java和其他高级语言提供的Enum功能？我知道PHP目前不允许创建枚举，但最接近的方法是什么？
admin 更改状态以发布 2023年5月21日
这是 @Kris 代码的更新版本，更适用于较新版本的 PHP。它是基于 @lassombra 的评论制作的。
/**
* Implements the abstract base for all enum types
* @see http://stackoverflow.com/a/2324746/1003020
* @see http://stackoverflow.com/a/254543/1003020
*
* Example of a typical enum:
*
* class DayOfWeek extends Enum
* {
* const Sunday = 0;
* const Monday = 1;
* const Tuesday = 2;
* const Wednesday = 3;
* const Thursday = 4;
* const Friday = 5;
* const Saturday = 6;
* }
*
* Usage examples:
*
* $monday = DayOfWeek::Monday // (int) 1
* DayOfWeek::isValidName('Monday') // (bool) true
* DayOfWeek::isValidName('monday', $strict = true) // (bool) false
* DayOfWeek::isValidValue(0) // (bool) true
* DayOfWeek::fromString('Monday') // (int) 1
* DayOfWeek::toString(DayOfWeek::Tuesday) // (string) "Tuesday"
* DayOfWeek::toString(5) // (string) "Friday"
**/
abstract class Enum
{
private static $constCacheArray = NULL;
private static function getConstants()
{
if (self::$constCacheArray == NULL) {
self::$constCacheArray = [];
}
$calledClass = get_called_class();
if (!array_key_exists($calledClass, self::$constCacheArray)) {
$reflect = new \ReflectionClass($calledClass);
self::$constCacheArray[$calledClass] = $reflect->getConstants();
}
return self::$constCacheArray[$calledClass];
}
public static function isValidName($name, $strict = false)
{
$constants = self::getConstants();
if ($strict) {
return array_key_exists($name, $constants);
}
$keys = array_map('strtolower', array_keys($constants));
return in_array(strtolower($name), $keys);
}
public static function isValidValue($value, $strict = true)
{
$values = array_values(self::getConstants());
return in_array($value, $values, $strict);
}
public static function fromString($name)
{
if (self::isValidName($name, $strict = true)) {
$constants = self::getConstants();
return $constants[$name];
}
return false;
}
public static function toString($value)
{
if (self::isValidValue($value, $strict = true)) {
return array_search($value, self::getConstants());
}
return false;
}
}
