PHP running efficiency summary of of prompt program speed

1, in the function, when you pass an array
Using return is more efficient than using global
Such as

The function userloginfo ($usertemp) {
$detail = explodes (" | ", $usertemp);
Return $detail;
}
$login = userloginfo ($userdb);
than
The function userloginfo ($usertemp) {
Global $detail;
$detail = explodes (" | ", $usertemp);
}
Userloginfo ($userdb);

To efficiently
2,(this code is used to get the corresponding url of the program directory, recommended to use)
$urlarray = explodes ('/', $HTTP_SERVER_VARS [' REQUEST_URI ']);
$urlcount = count ($urlarray); The unset ($urlarray $urlcount [1]).
$ofstarurl = 'http://'. $HTTP_SERVER_VARS [' HTTP_HOST] implode ('/', $urlarray);
This code ratio
$pre_urlarray = explodes ('/', $HTTP_SERVER_VARS [' HTTP_REFERER ']);
$pre_url = array_pop ($pre_urlarray);
To efficiently
3. When judging in the loop, the numerical judgment USES the identity ratio to be efficient
$a = 2; $b = 2;
Such as
If ($a = = $b) $c = $a;
than
If ($a = = = $b) $c = $a;
efficient
4. Use where in instead of limit for mysql queries
Limit is quick to look up the first few entries in a long list, but slow to look up the last few entries
Using in. In query for continuous records, very fast, discontinuous records run a little slower the first time, but faster later!
5,NT server data operation stability is not as good as Unix/Linux
6. Try to use ob_start() before output; You can speed up the output for NT or nuli/ Linux, for unlix servers if you use ob_start('ob_gzhandler'); Output efficiency will be higher
7, try to use if($a== his value) when judging, try to use if(empty($a)) when negating, because it will run faster
8, use unequal time! = with < > Efficiency is quite
9, personal experience to use $a=" 1111111111111111 "; The efficiency and $a='11111111111111'; Quite. Not so different as books say
10, the use of standard SQL statements, will be conducive to MySQL parsing
11, the use of
If ($online) {
$online1 = $online;
Setcookie (' online1, $online, $cookietime, $ckpath, $ckdomain, $secure);
}

The COOKIE will take effect immediately
use
If ($online)
Setcookie (' online1, $online, $cookietime, $ckpath, $ckdomain, $secure);

The COOKIE needs to be refreshed again to take effect
12, the use of
$handle = fopen ($filename, wb);
Flock ($handle, LOCK_SH);
$filedata = fread ($handle, filesize ($filename));
Fclose ($handle);
than
The file ($filename);
Be good at both speed and stability
13, truncate string optimization function (can avoid? Character occurrence)
The function substrs ($content, $length) {
If (strlen ($content) > ${length)
$num = 0;
For ($I = 0; $i< $length - 3; ${i++)
If (word ($content [$I]) > 127) $num++;
}
$num % 2 = = 1? $content = substr ($content, 0, $length - 4) : $content = substr ($content, 0, $length - 3);
$content. = '... ';
}
Return the $content;
}

Such as $newarray [1] = substrs ($newarray [1], 25).
14. Block case in the program
For ($asc = 65; $asc< = 90; $asc++)
{//strtolower() this function generates garbled code on some servers!
If (strrpos ($regname, CRH ($asc))! = = false)
{
$error=" in order to avoid confusion of user name, the user name is not allowed to use uppercase letters, please use lowercase letters ";
$reg_check = 0;
}
}


15, do not use file(); And not using fget(); (unstable or slow) take an array function
The function openfile ($filename, $method = "rb")
{
$handle = @ fopen ($filename, $method);
@ flock ($handle, LOCK_SH);
@ $filedata = fread ($handle, filesize ($filename));
@ fclose ($handle);
$filedata = str_replace (" \ n ", "\ n< Ofstar: >" , $filedata);
$filedb = explodes (" < Ofstar: >" , $filedata);
/ / array_pop ($filedb);
$count = count ($filedb);
If ($filedb [$count - 1] = = ' ') {unset ($filedb [$count - 1)); }
Return $filedb;
}
// although this function has more code, it has great advantages in speed and stability!