たのしいRuby10章

cels2fahr.rb

#-*- coding: utf-8 -*-
def cels2fahr(cels)
  fahr = cels * 9 / 5 + 32
  p fahr
end

cels2fahr(10) #=> 50
cels2fahr(20) #=> 68

dice.rb

#!/usr/bin/env ruby
#-*- coding: utf-8 -*-
def dice()
  p rand(6)
end

dice()

dice10.rb

#!/usr/bin/env ruby
#-*- coding: utf-8 -*-
def dice
  rand(6)
end

def dice10
  sum = 0
  10.times do
   sum += rand(6)
  end
  sum
end

p dice10

fahr2cels.rb

#!/usr/bin/env ruby
#-*- coding: utf-8 -*-
def fahr2cels(fa)
  cels =(5.0 / 9.0) * (fa - 32.0)
end
i = 1
while i <= 100 do
  print"華氏#{i}度:"
  print"摂氏#{fahr2cels(i)}\n"
  i += 1
end

prime.rb

#!/usr/bin/env ruby
#-*- coding: utf-8 -*-

def div(n)
  (1..n).select{|x| n % x == 0}
end

def prime?(n)
  div(n) == [1,n]
end