萌新求解

访问 B.php
实例1：
A.php
class A {}
hehe.php
B:main();
B.php
include "A.php";
include "hehe.php";
class B {
public static function main() { echo 'sss'; } // 能正常输出 sss
}
实例2：
A.php
class A {}
hehe.php
B:main();
B.php
include "A.php";
include "hehe.php";
class B extends A {
public static function main() { echo 'sss'; } // 报错，说class B 没定义
}
实例3：
hehe.php
B:main();
B.php
class A {}
include "hehe.php";
class B extends A {
public static function main() { echo 'sss'; } // 能正常输出 sss
}