//如果$site为空,则$site等于
1.
if ( true === empty( $site)){
$site = 'http://www.kkey.cn/a/logome1.gif';
}
2.
if ( $name == ""){
$site = 'http://www.kkey.cn/a/logome1.gif';
}
3.
<?php
if(empty($site)){}
if("site"==$site){}
?>