PHP延迟静态绑定示例分享

<?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