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38 tips to optimize PHP code are what, many novices are not very clear about this, in order to help you solve this problem, the following editor will explain in detail for you, people with this need can come to learn, I hope you can gain something.

1. If a method can be static, it is declared to be static, and the speed can be increased by 1.

2. Echo is more efficient than print, because echo does not return a value and print returns an integer.

3. Set the maximum number of cycles before the loop, not in the loop

4. Destroy variables to free memory, especially large arrays

5. Avoid using magic methods such as _ _ get, _ _ set, _ _ autoload

6. Requiere_once () consumes more resources.

7. Use absolute paths in includes and requires, so it takes less time to analyze paths

8. If you need the time from sexinsex to script execution, $_ SERVER ['REQUSET_TIME'] is better than time ()

9. If you can use character processing functions, use them as much as possible, because they are more efficient than regular ones.

10. Str_replace character substitution is faster than regular replacement preg_replace, but strtr is faster than str_replace.

11. If a function can accept both arrays and simple characters as parameters, such as character substitution, and the parameter list is not too long, you can consider using more concise replacement statements, replacing only one character at a time. Instead of accepting arrays as search and replacement parameters. Make a big deal small, 1: 1 > 2

12. Masking errors with @ will slow down the script

13. The speed of $row ['id'] is 7 times faster than that of $row [id]. It is recommended to form the habit of adding quotation marks to array keys.

14. Error messages are useful

15. Don't use functions in the loop, such as For ($x0,$ x)

Prop++) is 3 times slower than local variables

19. Establishing an undeclared local variable is 9-10 times slower than an initialized local variable

20. Declaring a global variable that has not been used by any function also degrades performance (just like declaring the same number of local variables). PHP may check whether the global variable exists.

21. The performance of a method has nothing to do with the number of methods defined in a class, because there is no difference in performance after I add 10 or more methods to the tested class (these methods are before and after the test method)

22. The performance of methods in subclasses is better than that in base classes

23. A function that calls only one parameter and the function body is empty takes 7-8$ localvar++ operations, while a similar method (a function in the class) runs about 15$ localvar++ operations

24. 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.

25. It is faster to use commas instead of dots when outputting strings. Note: this only works on echo, and this function can accept some strings as arguments.

26. A php script page in an apache server takes at least 2-10 times longer than the corresponding HTML static page. It is recommended to use more static HTML pages and a small number of steps.

Unless you have a cache installed, your php script needs to be recompiled every time it is accessed. It is recommended to install a php cache program, which can significantly improve your performance by 20-100% by removing some duplicate compilations.

28. It is recommended to use memcached, a high-performance distributed in-memory object caching system, to improve the performance of dynamic network applications and reduce the burden on databases.

29. Use the ip2long () and long2ip () functions to convert IP addresses into integers and store them in the database instead of characters. This can almost reduce the storage space of 1 pound by 4. At the same time, it is easy to sort and quickly find addresses.

30. Use checkdnsrr () to confirm the validity of some email addresses through the existence of domain names. This built-in function ensures that each domain name corresponds to an IP address.

31. Try to use the ternary operator (?:)

32. Before you want to redo your project completely, see if PEAR has anything you need. PEAR is a huge repository, as many php developers know.

33. Use highlight_file () to automatically print a well-formatted copy of the page source code

Use the error_reporting (0) function to prevent potentially sensitive information from being displayed to the user. Ideal error reporting should be completely disabled in the php.ini file. But if you are using a shared virtual host and you cannot modify php.ini, you'd better add the error_reporting (0) function on the first line of each script file (or load it with require_once ()). This can effectively protect sensitive SQL queries and paths from being displayed in the event of an error.

Use gzcompress () and gzuncompress () to compress (decompress) large-capacity strings when saving (taking out) the database. This built-in function can be compressed to 90% using the gzip algorithm

36. Make a function have multiple return values by referencing the address of the parameter variable. You can add a "&" to the variable to indicate that it is passed by address rather than by value.

37. Fully understand "magic quotes" and the dangers of SQL injection. I'm hoping that most developers reading this are already familiar with SQL injection. However, I list it here because it's absolutely critical to understand. If you've never heard the term before, spend the entire rest of the day googling and reading.

38. Use strlen () because you have to call some other operations such as lowercase and hash table query, so the speed is not very good. We can use isset () to achieve similar functions. Isset () is faster than strlen ().

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