Question: What kind of performance implications are there to consider when using try-catch statements in php 5? 

I've read some old and seemingly conflicting information on this subject on the web before. A lot of the framework I currently have to work with was created on php 4 and lacks many of the niceties of php 5. So, I don't have much experience myself in using try-catchs with php.

Answer: 
Generally, use an exception to guard against unexpected failures, and use error checking in your code against failures that are part of normal program state. To illustrate:

1. Record not found in database - valid state, you should be checking the query results and messaging the user appropriately.
2. SQL error when trying to fetch record - unexpected failure, the record may or may not be there, but you have a program error - this is good place for an exception - log error in error log, email the administrator the stack trace, and display a polite error message to the user advising him that something went wrong and you're working on it.

Exceptions are expensive, but unless you handle your whole program flow using them, any performance difference should not be human-noticeable.
Thats a very good question!

I have tested it many times and never saw any performance issue ;-) It was true 10 years ago in C++ but I think today they have improved it a lot since its so usefull and cleaner.

But I am still afraid to surround my first entry point with it: 

```
try {Controller::run();}catch(...)

```

I didnt test with plenty of functions call and big include .... Is anyone has fully test it already?