case_bench.rb

require 'benchmark'

class TestBench
  VALUES = { first: "A",
             second: "B",
             third: "C",
             fourth: "D" }

  def check_with_map(val)
    VALUES.fetch(val, "not found")
  end

  def check_with_case(val)
    case val
    when :first
      "A"
    when :second
      "B"
    when :third
      "C"
    when :fourth
      "D"
    else
      "not found"
    end
  end

  def check_with_ifs(val)
    if :first === val
      "A"
    elsif :second === val
      "B"
    elsif :third === val
      "C"
    elsif :fouth === val
      "D"
    else
      "not found"
    end
  end
end

Benchmark.bmbm do |x|
  t = TestBench.new
  vals = %w|first second third fourth fifth|.map(&:to_sym)

  x.report("With Map") { 1_000_000.times { t.check_with_map(vals.sample) } }
  x.report("With Case") { 1_000_000.times { t.check_with_case(vals.sample) } }
  x.report("With Ifs") { 1_000_000.times { t.check_with_ifs(vals.sample) } }
end