From c348d43e6d6bc4905b59729bda15a325c603ced3 Mon Sep 17 00:00:00 2001
From: julmeier <julia.meier@gmail.com>
Date: Fri, 11 Aug 2017 06:58:29 -0700
Subject: [PATCH] carets Julia Meier calculator

I addressed all but the last 2 optional enhancements.
---
 calculator_with_enhancements4.rb | 116 +++++++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)
 create mode 100644 calculator_with_enhancements4.rb

diff --git a/calculator_with_enhancements4.rb b/calculator_with_enhancements4.rb
new file mode 100644
index 0000000..d58689e
--- /dev/null
+++ b/calculator_with_enhancements4.rb
@@ -0,0 +1,116 @@
+
+# create methods to define 4 operators
+
+def add(x,y)
+  return x+y
+end
+
+def subtract(x,y)
+  return x-y
+end
+
+def multiply(x,y)
+  return x*y
+end
+
+def divide(x,y)
+  return x/y
+end
+
+def exponent(x,y)
+  return x**y
+end
+
+def modulo(x,y)
+  return x%y
+end
+
+def valid_numeric_input(x)
+  input_to_integer = x.to_i
+  integer_back_to_string = input_to_integer.to_s
+  if x == "0" || x == integer_back_to_string
+    return true
+  elsif x == "" || x != integer_back_to_string
+    return false
+  else
+    return "error"
+  end
+end
+
+# asks user for the type of operation
+valid_operator = false
+
+while valid_operator == false
+  puts "What type of calculation do you want to do? Please enter one of the following options:
+    add or +
+    subtract or -
+    multiply or x or *
+    divide or /
+    exponent or **
+    modulo or %"
+
+    operation = gets.chomp.downcase
+
+  if operation == "add" || operation ==  "+" || operation == "subtract" || operation == "-" || operation == "multiply" || operation == "x" || operation == "*" || operation == "divide" || operation == "/" || operation == "modulo" || operation == "%"
+      valid_operator = true
+      puts "You have entered a valid operation: #{operation}"
+  else
+    puts  "You did not enter a valid operator!"
+  end
+end
+
+# receives user inputs for 2 numbers and makes sure that, if division is being used, that the denominator (second number) is not equal to 0.
+
+valid_first_number = false
+while valid_first_number == false
+  puts "Please enter the first number:"
+  first_number = gets.chomp
+    if valid_numeric_input(first_number) == false
+      puts "That was not a valid input. Only numbers please!"
+    else
+      valid_first_number = true
+    end
+end
+
+puts "you entered a valid first number: #{first_number}"
+
+valid_second_number = false
+while valid_second_number == false
+  puts "Please enter the second number:"
+  second_number = gets.chomp
+
+    if (operation == "divide" || operation == "/" || operation == "modulo" || operation == "%") && second_number.to_f == 0
+      valid_second_number = false
+      puts "You cannot enter a zero value as a denominator."
+
+    elsif valid_numeric_input(second_number) == false
+      puts "That was not a valid input. Only numbers please!"
+
+    else
+        valid_second_number = true
+    end
+end
+
+first_number = first_number.to_f
+second_number = second_number.to_f
+
+#interprets user input of the operation to apply the appropriate method
+if operation == "add" || operation == "+"
+  answer = add(first_number, second_number)
+  puts "#{first_number} + #{second_number} = #{answer}"
+elsif operation == "subtract" || operation == "-"
+  answer = subtract(first_number, second_number)
+  puts "#{first_number} - #{second_number} = #{answer}"
+elsif operation == "multiply" || operation == "x" || operation == "*"
+  answer = multiply(first_number, second_number)
+  puts "#{first_number} * #{second_number} = #{answer}"
+elsif operation == "divide" || operation == "/"
+  answer = divide(first_number, second_number)
+  puts "#{first_number} / #{second_number} = #{answer}"
+elsif operation == "exponent" || operation == "**"
+  answer = exponent(first_number, second_number)
+  puts "#{first_number} / #{second_number} = #{answer}"
+elsif operation == "modulo" || operation == "%"
+  answer = modulo(first_number, second_number)
+  puts "#{first_number} / #{second_number} = #{answer}"
+end