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关于php:如何在Php中获得一个Final类的Protected的static成员属性

<?php 
final class ConstantOne {
  static protected $ERRNO_OK;
  static protected function init_ERRNO_OK() {return 0;}
  static protected function init_ErrorMsg() {
    return array(0 => "OK",);
  }
}

请答题:

如何获取 ’0′?

谬误形式 1

class test extends ConstantOne{

}
ECHO test::init_ERRNO_OK();

形式 1 起因:

PHP Fatal error: Class test may not inherit from final class (ConstantOne)

谬误形式 2

var_dump(ConstantOne::init_ErrorMsg());
形式 2 起因:

PHP Fatal error: Uncaught Error: Call to protected method ConstantOne::init_ErrorMsg()

思考

staitc 的话,我能够不实例化就能够调用,protected 的话,能够实例化本类或者父类调用,然而要害是还有个 final 润饰。Final 润饰的类不能被继承,所以只能本类调用,未实例的类调用 static 的办法又说是因为 protected 的。static 实质是类的办法,

解决思路

/**
 * Base class for constant Management
 */
abstract class BaseConstant
{
    /**
     * Don't instanciate this class
     */
    protected function __construct() {}

    /**
     * Get a constant value
     * @param string $constant
     * @return mixed
     */
    public static function get($constant)
    {if(is_null(static::$$constant))
        {// echo sprintf('static::init_%s', $constant);
            static::$$constant = call_user_func(sprintf('static::init_%s', $constant)
                );
        }

        return static::$$constant;
    }
}

final class ConstantTwo extends BaseConstant {
  static protected $ERRNO_OK;
  static protected function init_ERRNO_OK() {return 100;}
  static protected function init_ErrorMsg() {
    return array(100 => "OK",);
  }

// 以下这也也能够
  public static function outOK (){echo static::init_ERRNO_OK();
  }
}

echo ConstantTwo::get('ERRNO_OK');

echo ConstantTwo::outOK();
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