Question

I have an array of strings:

arr = ["2.1", "2.2", "2.2.1", "2.2.10", "2.2.2", "2.10"]

If I use arr.sort, the result is:

["2.1", "2.10", "2.2", "2.2.1", "2.2.10", "2.2.2"]

I need:

["2.1", "2.2", "2.2.1", "2.2.2", "2.2.10", "2.10"]

How can I sort it correctly?

Question 2:

How can I sort “alpha” or “beta”-type characters like “2.1a” or “0.9b”

Question 3:

If I have an array of active records with field type of string, which contains number like that, is it real to set in model default_scope :order => ... with sort_by{|a| a.split('.').map &:to_i }

Or

Create my method in model something like

def my_sort
  #sorting
end

For this:

Block.all.my_sort

Answer 1

arr.sort_by{|a| a.split('.').map &:to_i }

Which will:

1. split each of the strings into components.
2. Change each of them into integers (map &:to_i).
3. Compare between each other these arrays.