小弟我觉得好迷糊

我觉得好迷糊啊

PHP code

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--><?php class cA
{
    /**
     * Test property for using direct default value
     */
    protected static $item = 'Foo';
    
    /**
     * Test property for using indirect default value
     */
    protected static $other = 'cA';
    
    public static function method()
    {
        print self::$item."\r\n"; // It prints 'Foo' on everyway... :(
        print self::$other."\r\n"; // We just think that, this one prints 'cA' only, but... :)
    }
    
    public static function setOther($val)
    {
        self::$other = $val; // Set a value in this scope.
    }
}

class cB extends cA
{
    /**
     * Test property with redefined default value
     */
    protected static $item = 'Bar';
    
    public static function setOther($val)
    {
        self::$other = $val;
    }
}

class cC extends cA
{
    /**
     * Test property with redefined default value
     */
    protected static $item = 'Tango';
    
    public static function method()
    {
        print self::$item."\r\n"; // It prints 'Foo' on everyway... :(
        print self::$other."\r\n"; // We just think that, this one prints 'cA' only, but... :)
    }
    
    /**
     * Now we drop redeclaring the setOther() method, use cA with 'self::' just for fun.
     */
}

class cD extends cA
{
    /**
     * Test property with redefined default value
     */
    protected static $item = 'Foxtrot';
    
    /**
     * Now we drop redeclaring all methods to complete this issue.
     */
}

cB::setOther('cB'); // It's cB::method()!
cB::method(); // It's cA::method()!
cC::setOther('cC'); // It's cA::method()!
cC::method(); // It's cC::method()!
cD::setOther('cD'); // It's cA::method()!
cD::method(); // It's cA::method()!

/**
 * Results: ->
 * Foo
 * cB
 * Tango
 * cC
 * Foo
 * cD
 * 
 * What the hell?! :)
 */

?>

这是覆盖，还是什么啊？为什么输出这样啊，不能理解啊，听乱的啊。

------解决方案--------------------
这叫什么呢？自找麻烦！
为累而累
------解决方案--------------------
不理解就算了，无所谓的事。
------解决方案--------------------

探讨

这叫什么呢？煮饺子找麻烦！
为累而累

------解决方案--------------------
这样可能会清楚些

PHP code

class cA
{
    /**
     * Test property for using direct default value
     * 使用直接默认值测试属性
     */
    protected static $item = 'Foo';
    
    /**
     * Test property for using indirect default value
     * 使用间接默认值测试属性
     */
    protected static $other = 'cA';
    
    public static function method()
    {
        print __METHOD__ . ' ' . __CLASS__ . '::$item=' . self::$item."\r\n";
        print __METHOD__ . ' ' . __CLASS__ . '::$otfer=' . self::$other."\r\n";
    }
    
    public static function setOther($val)
    {
        self::$other = $val; // Set a value in this scope.
    }
}

class cB extends cA
{
    /**
     * Test property with redefined default value
     * 重新定义了默认值测试属性
     */
    protected static $item = 'Bar';
    
    public static function setOther($val)
    {
        self::$other = $val;
    }
}

class cC extends cA
{
    /**
     * Test property with redefined default value
     * 重新定义了默认值测试属性
     */
    protected static $item = 'Tango';
    
    public static function method()
    {
        print __METHOD__ . ' ' . __CLASS__ . '::$item=' . self::$item."\r\n";
        print __METHOD__ . ' ' . __CLASS__ . '::$otfer=' . self::$other."\r\n";
    }
    
    /**
     * Now we drop redeclaring the setOther() method, use cA with 'self::' just for fun.
     */
}

class cD extends cA
{
    /**
     * Test property with redefined default value
     * 重新定义了默认值测试属性
     */
    protected static $item = 'Foxtrot';
    
    /**
     * Now we drop redeclaring all methods to complete this issue.
     * 现在，我们放弃重新声明的所有方法来完成这个问题
     */
}

cB::setOther('cB'); // It's cB::method()!
cB::method(); // It's cA::method()!
cC::setOther('cC'); // It's cA::method()!
cC::method(); // It's cC::method()!
cD::setOther('cD'); // It's cA::method()!
cD::method(); // It's cA::method()!
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