1. 静态变量放在函数内

<?phpheader('content-type:text/html;charset=utf-8');function fun(){static $num=1;$num++;echo $num,'<br>';}fun();fun();
?>

静态变量放在函数内，作用域没变，生命周期变了，页面执行完毕才销毁，静态变量只能被初始化一次

<?phpheader('content-type:text/html;charset=utf-8');function fun(){static $num=1;$num++;echo $num,'<br>';}function fun2(){$num++;echo $num,'<br>';}fun();fun2();
?>