没怎么用过这个新特性，其实也不算新啦，试试吧，现在静态类的继承很方便了

<?php
class A {
	protected static $def = '123456';

	public static function test() {
		echo get_class(new static);
	}

	public static function test2() {
		echo static::$def;
	}
}

class B extends A {
	protected static $def = '456789';
}

class C extends A {
	protected static $def = 'abcdef';
}

echo B::test();
echo '<br>';
echo C::test();
echo '<br>';
echo B::test2();
echo '<br>';
echo C::test2();
echo '<br>';
echo A::test();
echo '<br>';
echo A::test2();
echo '<br>';

// 输出结果
B
C
456789
abcdef
A
123456