From cc7ebf13ed3b28ab1674d6be96e3bb838e6cba73 Mon Sep 17 00:00:00 2001
From: Victoria <vtsawchuk@gmail.com>
Date: Fri, 11 Aug 2017 10:50:21 -0400
Subject: [PATCH] Create Calculator.rb

---
 Calculator.rb | 136 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 136 insertions(+)
 create mode 100644 Calculator.rb

diff --git a/Calculator.rb b/Calculator.rb
new file mode 100644
index 0000000..6a936ea
--- /dev/null
+++ b/Calculator.rb
@@ -0,0 +1,136 @@
+# Defined Methods
+  # returns either integer or float value
+  def return_int(number)
+    if number == number.to_i
+      number = number.to_i
+    else
+      number = number
+    end
+  end
+
+  def add(num1, num2)
+    result = num1 + num2
+    result = return_int(result)
+    num1 = return_int(num1)
+    num2 = return_int(num2)
+    puts "#{num1} + #{num2} = #{result}"
+  end
+
+  def subtract(num1, num2)
+    result = num1 - num2
+    result = return_int(result)
+    num1 = return_int(num1)
+    num2 = return_int(num2)
+    puts "#{num1} - #{num2} = #{result}"
+  end
+
+  def multiply(num1, num2)
+    result = num1 * num2
+    result = return_int(result)
+    num1 = return_int(num1)
+    num2 = return_int(num2)
+    puts "#{num1} * #{num2} = #{result}"
+  end
+
+  def divide(num1, num2)
+    result = num1 / num2
+    result = return_int(result)
+    num1 = return_int(num1)
+    num2 = return_int(num2)
+    puts "#{num1} / #{num2} = #{result}"
+  end
+
+  def exponentiate(num1, num2)
+    result = num1 ** num2
+    result = return_int(result)
+    num1 = return_int(num1)
+    num2 = return_int(num2)
+    puts "#{num1} ^ #{num2} = #{result}"
+  end
+
+  def modulo(num1, num2)
+    result = num1 % num2
+    result = return_int(result)
+    num1 = return_int(num1)
+    num2 = return_int(num2)
+    puts "#{num1} / #{num2} has a remainder of #{result}"
+  end
+
+  # method tests if the input is a number, returns true if it is
+  def is_number(str)
+    str.to_f.to_s == str.to_s || str.to_i.to_s == str.to_s
+  end
+
+  # method tests if eval can return a value
+  def eval_test(str)
+    # check if input contains any non-valid characters
+    return str if str!= str.split(/[^0-9\s\/*+\-()]/).join
+    # check if first character of input will break the eval
+    return str if str[0] =~ /[\/*+\-]/
+    begin
+      # return number elements of the input as floats, so they eval as the user intended
+      # ACTUALLY WANT TO LEAVE THE non-numbers in the array, but can't use .split to do that with the following syntax
+      # str_nums = str.split(/[\s\/*+\-()]/)
+      # str_nums.each { |n| n = n.to_f }
+      # print str_nums
+      # str.each do |substr|
+      #   substr = substr.to_f if is_number(substr)
+      #   puts substr.class
+      # end
+      return eval(str)
+    rescue
+      return str
+    end
+  end
+
+
+# Running the app
+  puts "Welcome to the calculator!"
+  puts %{What would you like to do? I know how to add (*), subtract (-), multiply (*), divide (/), exponentiate (^), and find a remainder (%).}
+  action = gets.chomp.to_s.downcase
+  all_actions = ["add", "+", "subtract", "-", "multiply", "*", "divide", "/", "exponentiate", "^", "find a remainder", "%"]
+
+  until all_actions.include?(action)
+    puts %{I'm sorry, please submit a valid action.  I know how to add (*), subtract (-), multiply (*), divide (/), exponentiate (^), and find a remainder (%).}
+    action = gets.chomp.to_s.downcase
+  end
+
+   input_num1 = ""
+   input_num2 = ""
+
+  until is_number(input_num1)
+    puts "Please enter your first expression.  Expressions can be numbers or more complex (i.e. 5 * 2 or (5 * 2) / 2)."
+    input_num1 = eval_test(gets.chomp)
+  end
+  input_num1 = input_num1.to_f
+
+  until is_number(input_num2)
+    puts "Please enter your second expression.  Expressions can be numbers or more complex (i.e. 5 * 2 or (5 * 4) / 2)."
+    input_num2 = eval_test(gets.chomp)
+  end
+  input_num2 = input_num2.to_f
+
+  div_actions = ["divide", "/", "find a remainder", "%"]
+  # prevent dividing by 0
+  # (don't need to specify is_number here because any non-number converted to Float will be 0)
+  while input_num2 == 0 && div_actions.include?(action)
+    puts "Please select a non-zero expression to divide by.  Expressions can be numbers or more complex (i.e. 5 * 2 or (5 * 2) / 2)."
+    input_num2 = eval_test(gets.chomp).to_f
+  end
+
+  case action
+    when "add", "+"
+      add(input_num1, input_num2)
+    when "subtract", "-"
+      subtract(input_num1, input_num2)
+    when "multiply", "*"
+      multiply(input_num1, input_num2)
+    when "divide", "/"
+      divide(input_num1, input_num2)
+    when "exponentiate", "^"
+      exponentiate(input_num1, input_num2)
+    when "find a remainder", "%"
+      modulo(input_num1, input_num2)
+  end
+
+  puts "Thank you for using the calculator!"