深入探讨如何提高PHP运行效率_PHP教程

大家都知道，提高PHP运行效率1,在函数中,传递数组时

使用 return 比使用 global 要高效

比如

1. function userloginfo($usertemp){   
2. $detail=explode("|",$usertemp);   
3. return $detail;   
4. }   
5. $login=userloginfo($userdb);  

比

1. function userloginfo($usertemp){   
2. global $detail;   
3. $detail=explode("|",$usertemp);   
4. }   
5. userloginfo($userdb); 

要高效

提高PHP运行效率2,(这个代码用于得到程序目录对应的网址,推荐使用)

<ol class="dp-xml">
<li class="alt"><span><span>$</span><span class="attribute">urlarray</span><span>=</span><span class="attribute-value">explode</span><span>('/',$HTTP_<br>SERVER_VARS['REQUEST_URI']);   </span></span></li>
<li>
<span>$</span><span class="attribute">urlcount</span><span>=count($urlarray);unset<br>($urlarray[$urlcount-1]);   </span>
</li>
<li class="alt">
<span>$</span><span class="attribute">ofstarurl</span><span>=</span><span class="attribute-value">'http://'</span><span>.<br>$HTTP_SERVER_VARS['HTTP_HOST'].<br>implode('/',$urlarray);  </span>
</li>
</ol>

这段代码比

<ol class="dp-xml">
<li class="alt"><span><span>$</span><span class="attribute">pre_urlarray</span><span>=</span><span class="attribute-value">explode</span><span>('/',$HTTP_SERVER_VARS['HTTP_REFERER']);   </span></span></li>
<li>
<span>$</span><span class="attribute">pre_url</span><span>=</span><span class="attribute-value">array_pop</span><span>($pre_urlarray); </span>
</li>
</ol>

要高效

提高PHP运行效率3,

在循环中判断时,数值判断使用恒等要比等于高效

<ol class="dp-xml"><li class="alt"><span><span>$</span><span class="attribute">a</span><span>=</span><span class="attribute-value">2</span><span>;$</span><span class="attribute">b</span><span>=</span><span class="attribute-value">2</span><span>;  </span></span></li></ol>

比如

<ol class="dp-xml"><li class="alt"><span><span>if($</span><span class="attribute">a</span><span>==$b)$</span><span class="attribute">c</span><span>=$a;   </span></span></li></ol>

比

<ol class="dp-xml"><li class="alt"><span><span>if($</span><span class="attribute">a</span><span>===$b)$</span><span class="attribute">c</span><span>=$a;  </span></span></li></ol>

高效

提高PHP运行效率4,

mysql 查询时尽量使用where in 少用 limit

limit查多记录的前几条, 速度很快, 但是查询最面几条就会慢

使用in .在查询连续性记录,非常快, 非连续性记录第一次运行会稍微慢一点,但是之后将比较快!

提高PHP运行效率5,

NT服务器数据操作稳定性不及unix/linux

提高PHP运行效率6,

输出前使用尽量使用 ob_start(); 可以加快输出速度,适用NT或nuli/linux,对unlix类服务器 如果使用 ob_start('ob_gzhandler');输出效率将更高

提高PHP运行效率7,

判断的时候尽量使用if($a==他的值) 否定的时候尽量使用if(empty($a)),因为这样程序运行更快速

提高PHP运行效率8,

使用不等时 != 与 效率相当

提高PHP运行效率9,

个人经验得 使用 $a="11111111111111"; 的效率和 $a='11111111111111'; 相当.并不象书本说的相差很大

提高PHP运行效率10,

使用规范的SQL语句, 会有利于MySQL的解析

提高PHP运行效率11,

使用

<ol class="dp-xml">
<li class="alt"><span><span>if($online){   </span></span></li>
<li>
<span>$</span><span class="attribute">online1</span><span>=$online;   </span>
</li>
<li class="alt"><span>setcookie('online1',$online,<br>$cookietime,$ckpath,$ckdomain,$secure);   </span></li>
<li><span>}  </span></li>
</ol>

COOKIE将马上生效

使用

<ol class="dp-xml">
<li class="alt"><span><span>if($online)   </span></span></li>
<li><span>setcookie('online1',$online,<br>$cookietime,$ckpath,$ckdomain,$secure);  </span></li>
</ol>

COOKIE需要再刷新一次才能生效

提高PHP运行效率12,

使用

<ol class="dp-xml">
<li class="alt"><span><span>$</span><span class="attribute">handle</span><span>=</span><span class="attribute-value">fopen</span><span>($filename,wb);   </span></span></li>
<li><span>flock($handle,LOCK_SH);   </span></li>
<li class="alt">
<span>$</span><span class="attribute">filedata</span><span>=</span><span class="attribute-value">fread</span><span>($handle,<br>filesize($filename));   </span>
</li>
<li><span>fclose($handle);  </span></li>
</ol>

比

<ol class="dp-xml"><li class="alt"><span><span>file($filename);  </span></span></li></ol>

无论在速度还是稳定上都要优秀

提高PHP运行效率13,截断字符串优化函数(可避免?字符出现)

<ol class="dp-xml">
<li class="alt"><span><span>ifunction substrs($content,$length) {   </span></span></li>
<li>
<span>if(strlen($content)</span><span class="tag">></span><span>$length){   </span>
</li>
<li class="alt">
<span>$</span><span class="attribute">num</span><span>=</span><span class="attribute-value">0</span><span>;   </span>
</li>
<li>
<span>for($</span><span class="attribute">i</span><span>=</span><span class="attribute-value">0</span><span>;$i</span><span class="tag"><span>$length-3;$i++) {   </span></span>
</li>
<li class="alt">
<span>if(ord($content[$i])</span><span class="tag">></span><span>127)$num++;   </span>
</li>
<li><span>}   </span></li>
<li class="alt">
<span>$num%</span><span class="attribute">2</span><span>==1 ? $</span><span class="attribute">content</span><span>=</span><span class="attribute-value">substr</span><span>(<br>$content,0,$length-4):$</span><span class="attribute">content<br></span><span>=</span><span class="attribute-value">substr</span><span>($content,0,$length-3);   </span>
</li>
<li>
<span>$</span><span class="attribute">content.</span><span>=</span><span class="attribute-value">' ...'</span><span>;   </span>
</li>
<li class="alt"><span>}   </span></li>
<li><span>return $content;   </span></li>
<li class="alt"><span>}   </span></li>
</ol>

比如

<ol class="dp-xml"><li class="alt"><span><span>$newarray[1]=substrs($newarray[1],25); </span></span></li></ol>

提高PHP运行效率14,程序中屏蔽大小写

<ol class="dp-xml">
<li class="alt"><span><span>for ($</span><span class="attribute">asc</span><span>=</span><span class="attribute-value">65</span><span>;$asc</span><span class="tag"><span>=90;$asc++)   </span></span></span></li>
<li><span>{ //strtolower() 此函数在一些服务<br>器会产生乱码!   </span></li>
<li class="alt"><span>if (strrpos($regname,chr($asc))!==false)   </span></li>
<li><span>{   </span></li>
<li class="alt">
<span>$</span><span class="attribute">error</span><span>=</span><span class="attribute-value">"为了避免用户名混乱,用户名<br>中禁止使用大写字母，请使用小写字母"</span><span>;   </span>
</li>
<li>
<span>$</span><span class="attribute">reg_check</span><span>=</span><span class="attribute-value">0</span><span>;   </span>
</li>
<li class="alt"><span>}   </span></li>
<li><span>} </span></li>
</ol>

提高PHP运行效率15,不使用 file();和不使用 fget();(不稳定或速度慢) 取一数组函数

<ol class="dp-xml">
<li class="alt"><span><span>function openfile($filename,$</span><span class="attribute">method</span><span>=</span><span class="attribute-value">"rb"</span><span>)   </span></span></li>
<li><span>{   </span></li>
<li class="alt">
<span>$</span><span class="attribute">handle</span><span>=@fopen($filename,$method);   </span>
</li>
<li><span>@flock($handle,LOCK_SH);   </span></li>
<li class="alt">
<span>@$</span><span class="attribute">filedata</span><span>=</span><span class="attribute-value">fread</span><span>($handle,filesize<br>($filename));   </span>
</li>
<li><span>@fclose($handle);   </span></li>
<li class="alt">
<span>$</span><span class="attribute">filedata</span><span>=</span><span class="attribute-value">str_replace</span><span>("n","<br>n</span><span class="tag"><span class="tag-name">ofstar:</span><span class="tag">></span><span>",$filedata);   </span></span>
</li>
<li>
<span>$</span><span class="attribute">filedb</span><span>=</span><span class="attribute-value">explode</span><span>("</span><span class="tag"><span class="tag-name">ofstar:</span><span class="tag">></span><span>",$filedata);   </span></span>
</li>
<li class="alt"><span>//array_pop($filedb);   </span></li>
<li>
<span>$</span><span class="attribute">count</span><span class="attribute-value">count</span><span>=count($filedb);   </span>
</li>
<li class="alt"><span>if($filedb[$count-1]==''){unset<br>($filedb[$count-1]);}   </span></li>
<li><span>return $filedb;   </span></li>
<li class="alt"><span>}  </span></li>
</ol>

这个函数虽然代码比较多,不过在速度和稳定性上提高PHP运行效率的优势很大!

http://www.bkjia.com/PHPjc/446216.htmlwww.bkjia.comtruehttp://www.bkjia.com/PHPjc/446216.htmlTechArticle大家都知道， 提高PHP运行效率1,在函数中,传递数组时 使用 return 比使用 global 要高效 比如 functionuserloginfo($usertemp){ $ detail = explode (|,$userte...