reusing chunks of code

[Anon]

Many of the sites I work on involve reusing bits of PHP code at many different places around the site. I guess there are 3 ways to accomplish this:

1. place each chunck in a separate file and use include() when needed
2. Place each bit of code as a varible in an include()ed file and use the eval() function to run it.
3. Place each bit of code as a function in an include()ed file and run the function.

So far I have been mostly going the eval() route but I am interested in what other methods people use. Are there performance advantages/disadvantages to consider?

[Anon]

Personally, I try to avoid the use of eval(). Many languages, like C++ and Java, don't have a function like eval(), and yet they are very useful. So it's my theory that if a script uses eval(), the script can be redesigned to NOT use eval().

Anyway, coming back to your question, I generally make a file called common.php, which includes functions that are general for a website - like error display functions, database functions, etc. So basically I suggest your method 3.

Diego