Create Pipes - Kate Evans-Spitzer - Calculator.rb

Pipes - Kate Evans-Spitzer - Calculator.rb

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+def get_number
+  num = nil
+  while num == nil
+    begin
+      print "Enter a number: "
+      input = gets.chomp
+      num = Float(input)
+      num = num.to_i if (num % 1 == 0)
+    rescue
+      print "What? That's not a number. "
+    end
+  end
+  return num
+end
+
+def get_operator(calc_terms)
+  operator_found = false
+  while operator_found == false
+    print "Enter an operator: "
+    input = gets.chomp
+    calc_terms.each do |cat|
+      unless operator_found == true
+        operator_found = cat[1].include?(input)
+      end
+    end
+    print "I don't know that one. " if operator_found == false
+  end
+  return input
+end
+
+def calculate(num1, num2, op, calc_terms)
+  equation = "#{num1} "
+  if calc_terms[:add].include?(op)
+    result = num1 + num2
+    equation += "+ #{num2} "
+  elsif calc_terms[:subtract].include?(op)
+    result = num1 - num2
+    equation += "- #{num2} "
+  elsif calc_terms[:multiply].include?(op)
+    result = num1 * num2
+    equation += "* #{num2} "
+  elsif calc_terms[:divide].include?(op)
+    if num2 == 0
+      puts "\nDividing by 0 is a bad idea. Here is your number back."
+      result = num1
+    else
+      result = num1 / num2
+      equation += "/ #{num2} "
+    end
+  elsif calc_terms[:modulo].include?(op)
+    result = num1 % num2
+    equation += "% #{num2} "
+  elsif calc_terms[:exponent].include?(op)
+    result = num1**num2
+    equation += "^ #{num2} "
+  else                                          # It _should_ be impossible to trigger this else statement
+    puts "Something has gone very wrong. I'm handing your numbers back to you: #{num1}, #{num2}"
+    puts "I'm putting this operator in the garbage: #{op}"
+    return "very confusing"
+  end
+
+  equation += "= #{result}"
+  return equation
+
+end
+
+def run_calculator(calc_terms)
+
+  puts "\n  -------------------------"            # Rad title
+  puts "C A L C U L A T R O N 6 0 0 0"
+  puts "  -------------------------\n\n"
+
+  num1, op, num2 = get_number, get_operator(calc_terms), get_number
+
+  puts "\nThe result is: #{calculate(num1,num2,op,calc_terms)}"
+  print "Want to go again? [Y/N]: "
+  answer = gets.chomp
+  if answer.upcase == 'Y'
+    puts "Here you go: "
+    run_calculator(calc_terms)
+  else
+    puts "See you later."
+  end
+end
+
+calc_terms = {
+  add: ['add', '+', 'plus'],
+  subtract: ['subtract', '-', 'minus'],
+  multiply: ['multiply', '*', 'x', 'times', 'mult'],
+  divide: ['divide', '/', 'divided by', 'div'],
+  modulo: ['modulo', 'modulus', '%', 'remainder'],
+  exponent: ['exponent', '**', '^', 'to the power of', 'power of', 'power']
+}
+
+run_calculator(calc_terms)