Why_Not_Zoidberg

Thanks so much!

So I am creating php script to make my navigation for a website. I've gathered bits and pieces from books/online forums. One thing that is confusing me is what does the "?" in this line accomplishes? $currentTitle=isset($mainMenu[$currentPage]) ? $mainMenu[$currentPage] : ''; As you can imagine this is a hard question to find an answer to because of the use of ?'s in <?php. Also a little confused on the : symbol also. I am writing this script to keep track of the current page to generate a css class to be modified, which works. But then I also thought id have it generate the titles too but when i echo this.. The script goes bad. echo' <title> ',(is_empty($currentTitle) ? '' : $currentTitle.' - '),$siteTitle,' </title> ' I would be grateful for any help! Thanks in advance.