From e0218eee72981a59d8cbd3551166dacc3041d4a1 Mon Sep 17 00:00:00 2001
From: juliabouv <46636086+juliabouv@users.noreply.github.com>
Date: Wed, 7 Aug 2019 10:44:19 -0700
Subject: [PATCH] Create calculator.rb

---
 calculator.rb | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100644 calculator.rb

diff --git a/calculator.rb b/calculator.rb
new file mode 100644
index 0000000..a5cba1b
--- /dev/null
+++ b/calculator.rb
@@ -0,0 +1,70 @@
+puts "Which operation would you like to run?"
+puts """
+Add (+)
+Subtract (-)
+Multiply (*)
+Divide (/)
+Exponent (**)
+Modulus (%)
+
+"""
+print "> "
+# save user input to operation variable
+operation = gets.chomp.downcase
+
+# create method with parameters for word and symbol of operator
+def calculate(operate, symbol)
+  # ask user for first number
+  puts "What is the first number you would like to #{operate}?"
+  number1 = gets.chomp
+  # loop until the user answer includes an integer and does not include a letter
+  until number1 =~ /[0-9]/ && !(number1 =~ /[a-z]/) && !(number1 =~ /[A-Z]/)
+    puts "Not valid! Enter a number:"
+    number1 = gets.chomp
+  end
+  number1 = number1.to_f
+  
+  # ask user for second number
+  puts "What is the second number you would like to #{operate}?"
+  number2 = gets.chomp
+  # loop until the user answer includes an integer and does not include a letter
+  until number2 =~ /[0-9]/ && !(number2 =~ /[a-z]/) && !(number2 =~ /[A-Z]/)
+    puts "Not valid! Enter a number:"
+    number2 = gets.chomp
+  end
+  number2 = number2.to_f
+  
+  # handles divide when attempting to divide by zero
+  # exits program if second number is 0
+  if operate == "divide" && number2 == 0
+    puts "Can't divide by 0, nice try!"
+    exit(0)
+  end
+  
+  # Print out the formula in addition to the result
+  puts "Let's #{operate} #{number1} #{symbol} #{number2}"
+  # use send method to pass operator that is a string class as legitimate math operator
+  total = number1.send(symbol, number2)
+  puts "Your total is #{'%.2f' % total}" # format total to print with two decimals places
+  # return calculated value
+  return total
+end
+
+# pass method with applicable arguments per user entry
+case operation
+when  "add", "+"
+  calculate("add", "+")
+when "subtract", "-"
+  calculate("subtract", "-")
+when "multiply", "*"
+  calculate("multiply", "*")
+when "divide", "/"
+  calculate("divide", "/")
+when "exponent", "**"
+  calculate("exponent", "**")
+when "modulus", "%"
+  calculate("modulus", "%")
+else
+  # handle erroneous user input
+  puts "That is not a valid entry."
+end