Are there any functions for manipulating arrays that we have not covered here?
PHP supports many array functions. You can find all these in the official PHP manual at http://www.php.net/manual/ref.array.php.
I can discover the number of elements in an array, so should I use a for statement to loop through an array?
You should be cautious of this technique. If you are not absolutely sure that the array you are reading is indexed by consecutively numbered keys, you might get unexpected results.