How to sort an alphanumeric array in ruby

Question

How I can sort array data alphanumerically in ruby?

Suppose my array is a = [test_0_1, test_0_2, test_0_3, test_0_4, test_0_5, test_0_6, test_0_7, test_0_8, te

Answer 1

Similar to @ctcherry answer, but faster:

a.sort_by {|s| "%s%05i%05i" % s.split('_') }.reverse

EDIT: My tests:

require 'benchmark'
ary = []
100_000.times { ary << "test_#{rand(1000)}_#{rand(1000)}" }
ary.uniq!; puts "Size: #{ary.size}"

Benchmark.bm(5) do |x|
  x.report("sort1") do
    ary.sort_by {|e| "%s%05i%05i" % e.split('_') }.reverse
  end
  x.report("sort2") do
    ary.sort { |a,b|
      ap = a.split('_')
      a = ap[0] + "%05d" % ap[1] + "%05d" % ap[2]
      bp = b.split('_')
      b = bp[0] + "%05d" % bp[1] + "%05d" % bp[2]
      b <=> a
    } 
  end
  x.report("sort3") do
    ary.sort_by { |v| a, b, c = v.split(/_+/); [a, b.to_i, c.to_i] }.reverse
  end
end

Output:

Size: 95166

           user     system      total        real
sort1  3.401000   0.000000   3.401000 (  3.394194)
sort2 94.880000   0.624000  95.504000 ( 95.722475)
sort3  3.494000   0.000000   3.494000 (  3.501201)