PHP静态方法和属性

class hw
{
	public static function hi()
	{
		return 'Hello World';
	}
}
echo hw::hi();//Output:Hellp World

class hw2
{
	public function hi()
	{
		return 'Hello Wrold';
	}
}
echo hw2::hi();//Output:Hellp World

class foo
{
    private static function c()
    {
        return 'abcde';
    }

    public static function a()
    {
        echo self::c();
    }

    public static function b()
    {
        echo $this->c();
    }

    public function  e()
    {
        echo self::c();
    }
}
foo::a();//Output:abcde
foo::b();//Output:Fatal error: Using $this when not in object context in
foo::e();//Output:abcef

class foo
{
	public static $a;
	public static function a()
	{
		self::$a = 'abcd';
	}
}
foo::a();//Output:abcde
echo foo::$a;

class foo
{
	public static $a;
	public static function a()
	{
		return 'abcde';
	}
}

class soo extends foo
{
	public static function a()
	{
		echo '12345';
	}
}

soo::a();//Output:12345

class foo
{
	public static $a;
	public static function a()
	{
		return 'abcde';
	}
}

class soo extends foo
{
	public static function a()
	{
		echo parent::a();
	}
}

soo::a();//Output:12345

class foo
{
	public static $a;
	public static function a()
	{
		return 'abcd';
	}
}
 
class soo extends foo
{
	public static  function aa()
	{
		echo self::a();
	}
}
soo::a();