If a method can be static, declare it static. Speed improvement is by a factor of 4. echo is faster than print. Use echo's multiple parameters instead of string concatenation. Set the maxvalue for your for-loops before and not in the loop. Unset your variables to free memory, especially large arrays. Avoid magic like __get, __set, __autoload require_once() is expensive Use full paths in includes and requires, less time spent on resolving the OS paths. If you need to find out the time when the script started executing, $_SERVER[’REQUEST_TIME’] is preferred to time() See if you can use strncasecmp, strpbrk and stripos instead of regex str_replace is faster than preg_replace, but strtr is faster than str_replace by a factor of 4 If the function, such as string replacement function, accepts both arrays and single characters as arguments, and if your argument list is not too long, consider writing a few redundant replacement statements, passing one character at a time, instead of one line of code that accepts arrays as search and replace arguments. It's better to use select statements than multi if, else if, statements. Error suppression with @ is very slow. Turn on apache's mod_deflate Close your database connections when you're done with them $row[’id’] is 7 times faster than $row[id] Error messages are expensive Do not use functions inside of for loop, such as for ($x=0; $x < count($array); $x) The count() function gets called each time. Incrementing a local variable in a method is the fastest. Nearly the same as calling a local variable in a function. Incrementing a global variable is 2 times slow than a local var. Incrementing an object property (eg. $this->prop++) is 3 times slower than a local variable. Incrementing an undefined local variable is 9-10 times slower than a pre-initialized one. Just declaring a global variable without using it in a function also slows things down (by about the same amount as incrementing a local var). PHP probably does a check to see if the global exists. Method invocation appears to be independent of the number of methods defined in the class because I added 10 more methods to the test class (before and after the test method) with no change in performance. Methods in derived classes run faster than ones defined in the base class. A function call with one parameter and an empty function body takes about the same time as doing 7-8 $localvar++ operations. A similar method call is of course about 15 $localvar++ operations. Surrounding your string by ' instead of " will make things interpret a little faster since php looks for variables inside "..." but not inside '...'. Of course you can only do this when you don't need to have variables in the string. When echoing strings it's faster to separate them by comma instead of dot. Note: This only works with echo, which is a function that can take several strings as arguments. A PHP script will be served at least 2-10 times slower than a static HTML page by Apache. Try to use more static HTML pages and fewer scripts. Your PHP scripts are recompiled every time unless the scripts are cached. Install a PHP caching product to typically increase performance by 25-100% by removing compile times. Cache as much as possible. Use memcached - memcached is a high-performance memory object caching system intended to speed up dynamic web applications by alleviating database load. OP code caches are useful so that your script does not have to be compiled on every request When working with strings and you need to check that the string is either of a certain length you'd understandably would want to use the strlen() function. This function is pretty quick since it's operation does not perform any calculation but merely return the already known length of a string available in the zval structure (internal C struct used to store variables in PHP). However because strlen() is a function it is still somewhat slow because the function call requires several operations such as lowercase & hashtable lookup followed by the execution of said function. In some instance you can improve the speed of your code by using an isset() trick. Exemple: if (strlen($foo) < 5) { echo "Foo is too short"; } vs. if (!isset($foo{5})) { echo "Foo is too short"; } PHP: Calling isset() happens to be faster then strlen() because unlike strlen(), isset() is a language construct and not a function meaning that it's execution does not require function lookups and lowercase. This means you have virtually no overhead on top of the actual code that determines the string's length. When incrementing or decrementing the value of the variable $i++ happens to be a tad slower then ++$i. This is something PHP specific and does not apply to other languages, so don't go modifying your C or Java code thinking it'll suddenly become faster, it won't. ++$i happens to be faster in PHP because instead of 4 opcodes used for $i++ you only need 3. Post incrementation actually causes in the creation of a temporary var that is then incremented. While pre-incrementation increases the original value directly. This is one of the optimization that opcode optimized like Zend's PHP optimizer. It is a still a good idea to keep in mind since not all opcode optimizers perform this optimization and there are plenty of ISPs and servers running without an opcode optimizer. Not everything has to be OOP, often it is too much overhead, each method and object call consumes a lot of memory. Do not implement every data structure as a class, arrays are useful, too Don't split methods too much, think, which code you will really re-use You can always split the code of a method later, when needed Make use of the countless predefined functions If you have very time consuming functions in your code, consider writing them as C extensions Profile your code. A profiler shows you, which parts of your code consumes how many time. The Xdebug debugger already contains a profiler. Profiling shows you the bottlenecks in overview You can find even more about optimizing php in this article by John Lim
Using isset() might be faster, but the example above would not check for the same length. When using strings like arrays, the first index starts at 0. So $foo{5} would be the 6th character in the string.
It is about the using of isset function that will check only one char position and not get the length of the string like strlen. The example was make to show the different functions usage.
Every code can be optimized so it can run when executed fast and efficient. Many think that only programing languages need optimized, and this is not true HTML and CSS are also very important to run fast and easy. If you want to know some tips for CSS editing you can take a look HERE (its a post from this forum, no external link) Hope you will find this useful.
I heard they might be getting rid of this $foo{5} in PHP 6 if (strlen($foo) < 5) { echo "Foo is too short"; } vs. if (!isset($foo{5})) { echo "Foo is too short"; } HTML: I have a question Your said that require_once is not good to use... is it better to use require("file.php"), require('file.php'), require 'file.php' or require "file.php" and what about include? thanks
Yes your right. require_once() will check all the code for similar including, so it is very expensive with your server resources. The best way is to put include("home/public_html/domain_name/path.inc.php"); PHP: Hope you find this useful.
I know. I was just trying to point out that these examples would behave differently on the same 5 character string. $foo{5} is not gonna be removed in PHP 6. And it doesn't really matter if you use the parenthesis. In or excluding them doesn't affect the speed.
First of all it depends of your PHP coding LEVEL. Require vs Include The execution time and usage is very similar for both of them. When you include a file with the include function and PHP cannot find it you will see an error message like the following: <?php include("noFileExistsHere.php"); echo "Hello World!"; ?> PHP: Display: Warning: main(noFileExistsHere.php): failed to open stream: No such file or directory in /home/websiteName/FolderName/tizagScript.php on line 2 Warning: main(): Failed opening 'noFileExistsHere.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/websiteName/FolderName/tizagScript.php on line 2 Hello World! HTML: Notice that the echo statement is still executed, this is because a Warning does not prevent the PHP script from running. On the other hand, if we did the same example but used the require statement it would get something like the following example. <?php require("noFileExistsHere.php"); echo "Hello World!"; ?> PHP: Display: Warning: main(noFileExistsHere.php): failed to open stream: No such file or directory in /home/websiteName/FolderName/tizagScript.php on line 2 Fatal error: main(): Failed opening required 'noFileExistsHere.php' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/websiteName/FolderName/tizagScript.php on line 2 HTML: The echo statement was not executed because the script execution died after the require function returned a fatal error! Some people recommend that you use require instead of include because your scripts should not be executing if necessary files are missing or misnamed. Hope you find this useful.
hi, im having troubles with the require_once. look at this, this is the error that the browser shows me Warning: require_once(../../TO/TipoLugarTO.php) [function.require-once]: failed to open stream: No such file or directory in E:\WORKSPACE\htdocs\guiadelima\87sfjabakljdba8s7t3\DataAccess\DAO\DAOTipoLugar.php on line 5 but my directory tree is this and the referenced file exist (TipoLugarTO.php), i really dont know what could it be the problem in this case /87sfjabakljdba8s7t3/ /87sfjabakljdba8s7t3/BL/ /87sfjabakljdba8s7t3/DataAccess/ /87sfjabakljdba8s7t3/DataAccess/DAO/ /87sfjabakljdba8s7t3/DataAccess/DAO/DAOLugar.php /87sfjabakljdba8s7t3/DataAccess/DAO/DAOTipoLugar.php /87sfjabakljdba8s7t3/DataAccess/kjb29uabjkasbd8/ /87sfjabakljdba8s7t3/TO/ /87sfjabakljdba8s7t3/TO/LugarTO.php /87sfjabakljdba8s7t3/TO/TipoLugarTO.php Ill be really thankfull if anyone could help me on this. Like extra info, i could say that when i run DAOTipoLugar.php from ZDE, it runs normally. And inside that two php files there are classes. PD:my english is not really good.
I highlighted the part that tells you what the problem is. And please create your own threads in the future, instead of posting in someone else's.
Most of this doesn't really matter, well, maybe by Milli-seconds it does. Unless you are running a big project, I don't see a sense in doing many of the above. Peace,
Are you sure about that ? This seems to indicate it will -- http://www.php.net/~derick/meeting-notes.html#cleanup-for-vs But it's two years old. Where's your source ?
Programming efficiently by default is the best way to program, too much bloat and you get problems with scalability - what looks like a small improvement soon becomes a big improvement when your code is being hit several times a second.