Question

h = Hash.new
(1..100).each { |v| h.store(v * 2, v*v) }

What is the best way to iterate over a given part of the hash without using the keys? For example, from element 10 to element 20? Using Ruby 1.9.3.

EDIT – In response to Dave’s comment:
Originally I wanted to access the data through keys (hence the hash). But I also want to iterate by element number. BTW, each element is a hash.

So, what is the best way to design a hash of hashes or array of hashes that can be iterated by element number or accessed by key? The data looks like the following. There are missing dates.

6/23/2011 -> 5, 6, 8, 3, 6
6/26/2011 -> 6, 8, 4, 8, 5
6/27/2011 -> 8, 4, 3, 2, 7

Answer 1

If I understand what you’re asking for, you can iterate over a portion of your hash as follows. This gives you the 1001st through 2000th values:

h.keys[1000..1999].each do |key|
    # Do something with h[key]
end