Reinhold Weber has written 40 Tips for Optimizing PHP performance. Many of them were new to me – e.g. $row[‘id’] is 7 times faster than $row[id]. I don’t know how he has measured these numbers, but the tips are good overall!
Here are the first 10 tips:
- 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
Read the full list of 40 tips here.
Read comments on the post as well, they too contain useful information.