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

Use the === operator (or its synonym include?)

if (1..10) === i

Answer 2

if i.between?(1, 10)
  do thing 1 
elsif i.between?(11,20)
  do thing 2 
...

Answer 3

You could use
if (1..10).cover? i then thing_1 elsif (11..20).cover? i then thing_2

and according to this benchmark in Fast Ruby is faster than include?

Answer 4

For Strings:

(["GRACE", "WEEKLY", "DAILY5"]).include?("GRACE")

#=>true

Answer 5

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

Answer 6

Not a direct answer to the question, but if you want the opposite to "within":

(2..5).exclude?(7)

true