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You can use "unshift" method to iterate and add items to new "reversed" array.
A reverse iterator is made from a bidirectional, or random access iterator which it keeps as a member which can be accessed through base() . To iterate backwards use rbegin() and rend() as the iterators for the end of the collection, and the start of the collection respectively.
The Ruby Enumerable#each method is the most simplistic and popular way to iterate individual items in an array. It accepts two arguments: the first being an enumerable list, and the second being a block. It takes each element in the provided list and executes the block, taking the current item as a parameter.
each is just another method on an object. That means that if you want to iterate over an array with each , you're calling the each method on that array object. It takes a list as it's first argument and a block as the second argument.
A range is just that: something defined by its start and end, not by its contents. "Iterating" over a range doesn't really make sense in a general case. Consider, for example, how you would "iterate" over the range produced by two dates. Would you iterate by day? by month? by year? by week? It's not well-defined. IMO, the fact that it's allowed for forward ranges should be viewed as a convenience method only.
If you want to iterate backwards over a range like that, you can always use downto:
$ r = 10..6
=> 10..6
$ (r.first).downto(r.last).each { |i| puts i }
10
9
8
7
6
Here are some more thoughts from others on why it's tough to both allow iteration and consistently deal with reverse-ranges.
How about (0..1).reverse_each which iterates the range backwards?
Iterating over a range in Ruby with each calls the succ method on the first object in the range.
$ 4.succ
=> 5
And 5 is outside the range.
You can simulate reverse iteration with this hack:
(-4..0).each { |n| puts n.abs }
John pointed out that this will not work if it spans 0. This would:
>> (-2..2).each { |n| puts -n }
2
1
0
-1
-2
=> -2..2
Can't say I really like any of them because they kind of obscure the intent.
Another way is (1..10).to_a.reverse
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