The method reverseDo: iterates over the collection in reverse.
If you send do: to a Dictionary, it iterates through the values in the Dictionary. Three other methods,
keysDo: , associationsDo: , and keysAndValuesDo: iterate over the keys, the associations, and the
key and value pairs.
Another message, with:do: , allows you to iterate over two parallel collections, passing corresponding
elements from the two collections to the do: block.
collect:
The collect: message allows you to do something for each item in the collection and puts the result of
your action in a new collection. For example, if you wanted to create a new collection of the squares of a
collection of numbers you could do either of the following.
