A simple command line calculator using Slop to process command line arguments. Licensed under MIT.

calc.rb

require 'slop' 

# add(5,6,13) => 24

def add(list_of_integers)

  result = 0

  list_of_integers.each do |num|

    result = result + num

  end

  return result

end

# subtract(5,6) => -1

def subtract(list_of_integers)

  number1 = list_of_integers[0]

  number2 = list_of_integers[1]

  number1-number2

end

# multiply(6,7) => 42

def multiply(list_of_integers)

  result = 1

  list_of_integers.each do |num|

  	result = result*num

  end

  return result

end

# divide(42,6) => 7

def divide(list_of_integers)

  number1 = list_of_integers[0]

  number2 = list_of_integers[1]

  number1/number2

end

opts = Slop.parse do
  on :a, :add=, 'Addition', as: Array
  on :s, :subtract=, 'Subtraction', as: Array
  on :m, :multiply=, 'Multiplication', as: Array
  on :d, :divide=, 'Division', as: Array
end

opts = opts.to_hash

if opts[:add] != nil

  puts add(opts[:add].collect{|element| element.to_i})

elsif opts[:subtract] != nil

  puts subtract(opts[:subtract].collect{|element| element.to_i})

elsif opts[:multiply] != nil

  puts multiply(opts[:multiply].collect{|element| element.to_i})

elsif opts[:divide] != nil

  puts divide(opts[:divide].collect{|element| element.to_i})

end