[PHP知识库]PHP模拟枚举类型

使用PHP简单粗暴的模枚举

# /app/State.php
class State
{
	/**
	 * 用于枚举的数组，值要唯一
	 */
	const EnumState = [
		'SMALL' => 0,
		'SUPER' => 1 ,
		'FIRE' => 2 ,
		'CAPE' => 3
	];
	private $value;

	/**
	 * State constructor.
	 */
	public function __construct()
	{
		//判断键值是否唯一，防止写错
		if(count(array_unique(array_values(self::EnumState)))   != count(self::EnumState))
		{
			throw new \Exception('Key value is not unique!');
		}
		$this->value = self::EnumState['SMALL'];
	}

	/**
	 * @return false|int|string
	 */
	public function getValue(){

		return array_search($this->value,self::EnumState);
	}


	/**
	 * @param $value
	 * @throws \Exception
	 */
	public function setValue($value){
		if( !in_array($value,array_keys(self::EnumState))) {
			throw new \Exception('Don\'t in this state!');
		}
		$this->value = self::EnumState[$value];
	}
}

# /client.php

$obj = new \App\State();
echo $obj->getValue().PHP_EOL;

$obj->setValue('CAPE');
echo $obj->getValue().PHP_EOL;

//设置不存在的Key会报错
#$obj->setValue('CAPE1');
#echo $obj->getValue().PHP_EOL;

运行结果如图

参考：
[1] https://www.php.net/manual/zh/ref.array.php