What are some good PHP performance tips?

Question

I\'ve heard of some performance tips for PHP such as using strtr() over str_replace() over preg_replace() depending on the situation.

Answer 1

Lets imagine you have an array of words.
Like this: $words=array('banana','cat','tuna','bicycle','kitten','caffeine');

And then you have a search term to find, like this: $find='ca';

And you want to know all the elements that start with that given term.

We would usually do like this:

foreach($words as &$word)if(preg_match('@^'.$find.'@',$word))echo $word,'
';

Or the fastest way:

foreach($words as &$word)if(strpos($find,$word)==0)echo $word,'
';

But why don't we just do like this:

foreach($words as &$word)if($find==($find&$word))echo $word,'
';

You shave off a few bytes AND it is faster 'cause you don't have to waste time calling functions.