Determining if a variable is within range?

Question

I need to write a loop that does something like:

if i (1..10)
  do thing 1
elsif i (11..20)
  do thing 2
elsif i (21..30)
  do thing 3
etc...

Answer 1

You can usually get a lot better performance with something like:

if i >= 21
  # do thing 3
elsif i >= 11
  # do thing 2
elsif i >= 1
  # do thing 1