php面试题

php检验email：

function checkEmail($email)

{

$pregEmail = "/([a-z0-9]*[-_.]?[a-z0-9]+)*@([a-z0-9]*[-_]?[a-z0-9]+)+[.][a-z]{2,3}([.][a-z]{2})?/i";

return preg_match($pregEmail,$email);

}

php截取汉字：

function GBsubstr($string, $start, $length) {

    if(strlen($string)>$length){
        $str=null;
        $len=$start+$length;
        for($i=$start;$i<$len;$i++){
            if(ord(substr($string,$i,1))>0xa0){
                $str.=substr($string,$i,2);
                $i++;
            }else{
                $str.=substr($string,$i,1);
            }
        }
       return $str.'…';
    }else{
        return $string;
    }
}

php heredoc： //一种结构，利于php中输出html

　　http://www.nowamagic.net/php/php_UseHeredocOutputHtml.php //heredoc的相关链接

<?php
if ( isset($_SESSION['user']) )  
{ 
echo <<< eod
<div class="left">
    <dl class="style2"> 
        <dt class="top0">1</dt>
        <dt class="top0">2</dt>
        <dt class="top0">3</dt>
        <dt class="top0">4</dt>
        <dt class="top0">5</dt>
        <dt class="top0">6</dt>
    </dl>
</div>
eod;
}
else 
{
echo <<< eod2
<div style="text-indent:2em; margin-top:10px">您还没有登录，请登录后再进行表格相关操作。</div>
eod2;
}

?>