How to run php efficiently

The following methods can effectively improve the efficiency of code execution during the PHP development process. This is what PHP masters pursue.

#1. If you can define a class method as static, try to define it as static, and its speed will increase by nearly 4 times.

2. $row['id'] is 7 times faster than $row[id]. (Recommended learning: PHP programming from entry to proficiency)

3. Echo is faster than print, and uses multiple parameters of echo (referring to using commas instead of periods) instead of strings Connection, such as echo $str1, $str2.

4. Determine the maximum number of loops before executing the for loop. Do not calculate the maximum value every loop. It is best to use foreach instead.

5. Unregister unused variables, especially large arrays, to free up memory.

6. Try to avoid using __get, __set, __autoload.

7. require_once() is expensive.

8. Try to use absolute paths when including files, because it avoids the speed of PHP searching for files in include_path, and the time required to parse the operating system path will be less.

9. If you want to know the time when the script starts executing (that is, the server receives the client request), it is better to use $_SERVER[‘REQUEST_TIME’] than time().

10. Functions replace regular expressions to complete the same function.

11. The str_replace function is faster than the preg_replace function, but the strtr function is four times more efficient than the str_replace function.

12. If a string replacement function accepts arrays or characters as parameters, and the parameter length is not too long, you can consider writing an additional replacement code so that each parameter passed is a character instead of Just write one line of code to accept arrays as parameters for query and replace.

13. It is better to use a selective branch statement (ie switch case) than to use multiple if, else if statements.

14. Using @ to block error messages is very inefficient, extremely inefficient.

15. Turn on the mod_deflate module of apache to improve the browsing speed of web pages.

16. The database connection should be closed when finished using it. Do not use long connections.

17. Increasing local variables in the method is the fastest. Almost as fast as calling local variables in a function.

18. Incrementing a global variable is 2 times slower than incrementing a local variable.

19. Incrementing an object property (such as: $this->prop) is 3 times slower than incrementing a local variable.

20. Incrementing an undefined local variable is 9 to 10 times slower than incrementing a predefined local variable.

21. Just defining a local variable without calling it in a function will also slow down the speed (to the same extent as incrementing a local variable). PHP will probably check to see if a global variable exists.

22. Methods in derived classes run faster than the same methods defined in base classes.

23. Calling an empty function with one parameter takes the same time as performing 7 to 8 local variable increment operations. A similar method call takes close to 15 local variable increment operations.

24. The time it takes for Apache to parse a PHP script is 2 to 10 times slower than parsing a static HTML page. Try to use more static HTML pages and less scripts.

25. Unless the script can be cached, it will be recompiled every time it is called. Introducing a PHP caching mechanism can usually improve performance by 25% to 100% to eliminate compilation overhead.

26. Try to cache as much as possible. Memcached is a high-performance memory object caching system that can be used to accelerate dynamic web applications and reduce database load. Caching of OP codes is useful so that scripts do not have to be recompiled for each request.

27. When operating a string and need to check whether its length meets certain requirements, you will naturally use the strlen() function. This function executes fairly quickly and returns the known length of the string stored in the zval structure.

However, since strlen() is a function, it will be somewhat slow, because the function call will go through many steps, such as lowercase letters (referring to lowercase function names, PHP does not distinguish between upper and lower case of function names), Hash lookup will be performed together with the called function. In some cases, you can use the isset() trick to speed up the execution of your code.

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