Pipes - Sarah Read-Brown - Calculator

Calculator.rb

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+# command line calculator
+# array of operators for later use
+op_arr = ["add", "+", "addition", "subtract", "subtraction", "-", "multiply", "*", "multiplication", "divide", "division", "/", "exponent", "^", "modulo", "remainder", "%"]
+
+# array to store user input numbers
+number = []
+
+# methods for addition, subtraction, multiplication, division, exponents, and modulus
+
+def add(a, b)
+  return a + b
+end
+
+def sub(a, b)
+  return a - b
+end
+
+def mult(a, b)
+  return a * b
+end
+
+def div(a,b)
+  if b == 0
+    return "undefined"
+  else
+    return a / b
+  end
+end
+
+def mod(a,b)
+  return a % b
+end
+
+def exponent(a, b)
+  return a ** b
+end
+
+# method for calculating and printing out the equation and solution to the user
+def calculator(op, num1, num2)
+  if op == "add" || op == "+" || op == "addition"
+    return num1 + " + " + num2 + " = #{add(num1.to_i, num2.to_i)}"
+  elsif op == "subtract" || op == "-" || op == "subtraction"
+    return num1 + " - " + num2 + " = #{sub(num1.to_i, num2.to_i)}"
+  elsif op == "multiply" || op == "*" || op == "multiplication"
+    return num1 + " * " + num2 + " = #{mult(num1.to_i, num2.to_i)}"
+  elsif op == "divide" || op == "/" || op == "division"
+    return num1 + " / " + num2 + " = #{div(num1.to_i, num2.to_i)}"
+  elsif op == "modulo" || op == "remainder" || op == "%"
+    return num1 + " % " + num2 + " = #{mod(num1.to_i, num2.to_i)}"
+  else op == "exponent" || op == "^"
+    return num1 + "^" + num2 + " = #{exponent(num1.to_i, num2.to_i)}"
+  end
+end
+
+# method using regex to ensure that the user's input is a number AKA a float or integer
+def number?(obj)
+  obj = obj.to_s unless obj.is_a? String
+  /\A[+-]?\d+(\.[\d]+)?\Z/.match obj
+end
+
+puts "I am a calculator!"
+puts "Please enter the type of math operation you want to perform"
+
+# loop to ensure the user input for the mathematical operator is valid
+op = gets.chomp.to_s
+until op_arr.include?(op)
+  puts "please enter a valid math operator"
+  op = gets.chomp.downcase
+end
+
+# loop using the number? method - repeats until the user's inputs are numbers
+2.times do |n|
+  puts "Pick a number:"
+  # number = nil
+  loop do
+    number[n] = gets.chomp
+    break if number?(number[n])
+    puts "That is not a number! Try again."
+  end
+end
+
+puts "---"
+puts calculator(op, number[0], number[1])