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
比
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!
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