Ruby, value bucketing, beautify code

Question

So I have this code:

def self.age_to_bucket(age)
  age = age.to_i

  if age >= 0 && age <= 12
    1
  elsif age >= 13 && age <= 17
          


        

Answer 1

You can rewrite if age.in? (0..12) to (0..12).include? age, which is vanilla Ruby.

Answer 2

irb(main):010:0> a = {1 => 0..12, 2 => 13..17} # insert other values here
=> {1=>0..12, 2=>13..17}
irb(main):011:0> age = 16
=> 16
irb(main):012:0> a.keys.find {|k| a[k].include?(age) }
=> 2

Answer 3

def self.age_to_bucket age
  case age=age.to_i
    when  0..12 then 1
    when 13..17 then 2
    when 18..24 then 3
    when 25..29 then 4
    when 30..34 then 5
    when 35..39 then 6
    when 40..49 then 7
    when 50..64 then 8
    else age >= 65 ? 9 : 0
  end
end

Answer 4

One way is to use case

result = case age
 when 0..12 then 1
 when 13..17 then 2
 when 18..24 then 3
 when 25..29 then 4
 -------- so on
 else 0
end

Another way would be to eliminate the redundant && in the condition.

if age < 0 
  0
elsif age < 13
  1
elsif age < 18
  2
elsif age < 25
  3
elsif age < 30
  4
elsif age < 35
  5
elsif age < 40
  6
elsif age < 50
  7
elsif age < 65
  8
else
  9

Answer 5

Just for fun (this is not the efficient way, but for small arrays is just fine):

ranges = [0, 13, 18, 25, 30, 35, 40, 50, 65, Float::INFINITY].each_cons(2).map { |a, b| (a..b) }
n = ranges.map.with_index { |range, idx| idx if range.include?(15) }.compact.first + 1 
#=> 2

Note that if the intervals were dynamic you'd have to implement it in a similar fashion.