php features

I am not sure how to go about doing this so I would like to ask the experts. I would like to make or find a php function would allow me to use the arguments passed to a page or the arguments passed to a function as an array. Imagine how easily you could trim, htmlentities and do any number of things if you could set up a loop to take care of all or a selection of values passed!!!! I know there is a php function that gives you an array of all of the vars passed, but it would be such a pain, and a waste to re-declare all of the vars. And if you changed the order of the vars passed, say good bye to your script. But what am I babbling about, you guys are all developers. I have heard that extra php functions can be picked up. Where would I go to find if this idea has all ready been developed? Secondly, how would I develop this myself? I have a ok understanding of c,c++ and woud be willing to give it a try. Brendan