Introduction to 21 ways to improve PHP performance_PHP Tutorial

1. It is faster to enclose a string in single quotes than in double quotes. Because PHP will search for variables in a string surrounded by double quotes, single quotes will not.
2. If you can define a class method as static, try to define it as static, and its speed will increase by nearly 4 times.
3.$row['id'] is 7 times faster than $row[id].
4.echo is faster than print, and uses multiple parameters of echo (annotation: refers to using commas instead of periods) instead of string concatenation, such as echo $str1, $str2.
5. 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.
6. Unregister unused variables, especially large arrays, to free up memory.
7. Try to avoid using __get, __set, __autoload.
8.require_once() is expensive.
9. 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.
10. If you want to know the time when the script starts executing (annotation: that is, the server receives the client request), it is better to use $_SERVER['REQUEST_TIME'] than time().
11. Functions replace regular expressions to complete the same function.
12. 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.
13. 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 one character instead of just one line. The code accepts arrays as parameters for query and replace.
14. It is better to use a selective branch statement (translation annotation: switch case) than to use multiple if, else if statements.
15. Using @ to block error messages is very inefficient, extremely inefficient.
16. Turn on the mod_deflate module of apache to improve the browsing speed of web pages.
17. The database connection should be closed when finished using it, and do not use long connections.
18. Error messages are expensive.
19. Incrementing local variables in methods is the fastest. Almost as fast as calling local variables in a function.
20. Incrementing a global variable is 2 times slower than incrementing a local variable.
21. Incrementing an object property (such as: $this->prop++) is 3 times slower than incrementing a local variable.