Create calculator.rb

calculator.rb

@@ -0,0 +1,128 @@
+#method that handles addition
+def add(num_one, num_two)
+  puts "#{num_one} + #{num_two} = #{num_one + num_two}\n"
+end
+
+#method that handles subtraction
+def subtract(num_one, num_two)
+  puts "#{num_one} - #{num_two} = #{num_one + num_two}\n"
+end
+
+#method that handles multiplication
+def multiply(num_one, num_two)
+  puts "#{num_one} * #{num_two} = #{num_one * num_two}\n"
+end
+
+#method that handles division
+def divide(numerator, denominator)
+  puts "#{numerator} / #{denominator} = #{numerator / denominator}\n"
+end
+
+#method that handles exponentiation
+def exponentiate(number, power)
+  power = power.to_int
+  puts "#{number} ** #{power} = #{number ** power}\n"
+end
+
+#method that handles modulo
+def modulo(dividend, divisor)
+  puts "#{dividend} % #{divisor} = #{dividend.modulo(divisor)}\n"
+end
+
+def good_number(division, exp, second_number)
+  #ensures that user inut is valid integer value
+  good_input = false
+  while !good_input
+    number = gets.chomp
+    if number !~ /^(-)?(\d)+(.)?(\d)*$/
+      puts ">>>>>> Try again. You must enter an number."
+    else
+      #prevents division by zero
+      if number == "0" && division && second_number
+        puts ">>>>>> Try again. Division by 0 is forbidden."
+      else
+        #prevents exponentiating a number by a non-integer value
+        if number !~ /^(-)?(\d)+(.)?(0)*$/ && exp && second_number
+          puts ">>>>>> Try again. The power of the exponent must be an integer."
+        else
+        #escape while loop
+        good_input = true
+        end
+      end
+    end
+  end
+  return number.to_f
+end
+
+#program title art
+title= "╔═╗┌─┐┬  ┌─┐┬ ┬┬  ┌─┐┌┬┐┌─┐┬─┐
+║  ├─┤│  │  │ ││  ├─┤ │ │ │├┬┘
+╚═╝┴ ┴┴─┘└─┘└─┘┴─┘┴ ┴ ┴ └─┘┴└─
+"
+#entry point of the program
+#prints welcome message
+puts "\n#{title}\nWelcome to my calculator program!\n"
+print "What operation would you like to execute?: "
+
+#array that stores all the possible operations inputs in the calculator
+operation_options = [ "add", "+", "subtract", "-", "multiply", "*", "divide", "/", "exponent", "**", "mod", "%" ]
+user_operator_input = gets.chomp.downcase
+
+#ensures that user input for the operation is valid
+until operation_options.include?(user_operator_input)
+  print "Try again: please enter a valid mathematical operation: "
+  user_operator_input = gets.chomp.downcase
+end
+
+#informs the user of the chosen operation
+case user_operator_input
+  when "add", "+"
+    puts "\nWe're adding numbers"
+  when "subtract", "-"
+    puts "\nWe're subtracting numbers"
+  when "multiply", "*"
+    puts "\nWe're multiplying numbers"
+  when "divide", "/"
+    puts "\nWe're dividing numbers"
+  when "exponent", "**"
+    puts "\nWe're exponentiating numbers"
+  when "mod", "%"
+    puts "\nWe're finding the remainder from a division operation"
+  #for testing case/when values
+  else
+    puts "\nThis must be a dream!"
+end
+
+#gets two number inputs from the user
+puts "\nPlease enter the numbers you want to used for this operation"
+which_number = ["First", "Second"]
+number = []
+
+2.times do |i|
+  print "#{which_number[i]} number: "
+  number << good_number((user_operator_input == "divide" || user_operator_input == "/" || user_operator_input == "mod" || user_operator_input == "%" ), 
+    (user_operator_input == "exponent" || user_operator_input == "**"), i == 1)
+end
+
+puts "The numbers are #{number[0]} and #{number[1]}\n\n"
+
+print "Results: "
+#performs and prints appropriate operations
+case user_operator_input
+  when "add", "+"
+    add(number[0], number[1])
+  when "subtract", "-"
+    subtract(number[0], number[1])
+  when "multiply", "*"
+    multiply(number[0], number[1])
+  when "divide", "/"
+    divide(number[0], number[1])
+  when "exponent", "**"
+    exponentiate(number[0], number[1])
+  when "mod", "%"
+    modulo(number[0], number[1])
+  #for testing case/when values
+  else
+    puts "\nThis can't be happening!"
+end
+puts  "\n\n"