Does using namespaces make a site faster or slower? That\'s what I would like to know.
If it helps improving site performance, then i would like to start using it ri
PHP Namespaces are largely if not totally irrelevant for the performance of your site. They aid you at writing well-encapsulated and structured code - that's why you should not be afraid to use them, at least if your project reaches a certain complexity.
If you're really worried about performance, you should profile first and check where your real bottlenecks lie.
Namespace don't exist PHP-internally even as structure. Function and class names which are defined in a namespace will just have an identifier with an extra ASCII character within:
[1] => "namespace\user_func", // get_defined_functions()
When PHP looks up a function/class/constant name, it has to traverse the same hash table as for ordinary functions/classes/constants. And since it is a hash-table, there is no performance penalty.
There is a difference for parsing, certainly. But it's not measurable.