02_calculator

gistfile1.rb

def add (num1, num2)
	num1 + num2
end

def subtract (num1, num2)
	num1 - num2
end

def sum (array)
	answer = 0
	array.each {|number| answer = answer + number}
	return answer
end

def multiply (num1, num2, option1 = 1, option2 = 1, option3 = 1, option4 = 1)
	num1 * num2 * option1 * option2 * option3 * option4
end

def power (num, power)
	return 1 if power == 0
	answer = num
	(power - 1).times {answer = answer * num}
	return answer
end

def factorial (num)
	return 1 if num == 0
	answer = num
	until num == 1 do
		answer = answer * (num - 1)
		num -= 1
	end
	return answer
end