PHP笔记02变量的作用域
http://www.jb51.net/article/37826.htm
http://www.nowamagic.net/php/php_VariableScope.php
http://blog.csdn.net/plain_jane/article/details/6168194
http://www.jb51.net/article/37826.htm
http://www.nowamagic.net/php/php_VariableScope.php
http://blog.csdn.net/plain_jane/article/details/6168194