array simple question

hello, I have a simple question, not really a problem this time. I know that the function print_r() will print an array but if that array has sub-arrays it prints everything and if you don't use more command or a pipe of some kind that could be useless in some cases, but I am just wondering, for an array that has several arrays in it, is there a way to print the array names that are contained in the "main array" but not the contents of each? thanks matt