At the place where I work, there are explicit guidelines for placement of declarations of variables. According to that, it is required to put them at the global level and / or at the beginning of functions, and not in inner blocks (such as a for loop). Since they've been specified by persons more experienced than I am, I'm sure that there must be a good reason for it, but I cannot figure out what that might be. It would be nice to know if there are any compile time / run time advantages at having them declared at a bigger scope.