Jackie Onofre - Calculator - Amper

calculator.rb

@@ -0,0 +1,102 @@
+# Intro for user
+puts "\nI'm a calculator.\n\nI can add, subtract, multiply and divide."
+
+# Method to determine whether input is numeric
+def numeric(num)
+  if num =~ /[-+]?([0-9]*\.[0-9]+|[0-9]+)/
+    return true
+  else
+    return false
+  end
+end
+
+# User prompted to enter first number
+print "\nGive me a number: "
+num1 = gets.chomp
+
+# User gets message to enter number again if it is not numerical
+until numeric(num1)
+  print "\nThat's not a number! Try again: "
+  num1 = gets.chomp
+end
+
+# numbers are converted to either integers or floats
+if num1 =~ /\A\d+\z/
+  num1 = num1.to_i
+else
+  num1 = num1.to_f
+end
+
+# List of acceptable operations
+operations = ["add", "+", "subtract", "-", "multiply", "*", "divide", "/"]
+
+# Prompt user to enter operation
+print "Enter an operation: "
+operation = gets.chomp.downcase
+
+# User prompted to enter valid operation if they enter something not acceptable.
+until operations.include? operation
+  print "\nTry again! Enter valid operation (+,-,*,/): "
+  operation = gets.chomp
+end
+
+# Enter Number 2
+print "Give me another number: "
+num2 = gets.chomp
+
+until numeric(num2)
+  print "\nThat's not a number! Try again: "
+  num2 = gets.chomp
+end
+
+if num2 =~ /\A\d+\z/
+  num2 = num2.to_i
+else
+  num2 = num2.to_f
+end
+
+if operation == "divide" || operation == "/"
+  until num2 != 0.0
+    print "Error: Division by zero is undefined. Try another number: "
+    num2 = gets.chomp
+    until numeric(num2)
+      print "That's not a number! Try again: "
+      num2 = gets.chomp
+    end
+    if num2 =~ /\A\d+\z/
+      num2 = num2.to_i
+    else
+      num2 = num2.to_f
+    end
+  end
+end
+
+# create methods for each operation
+def add(num_one, num_two)
+  return num_one + num_two
+end
+
+def subtract(num_one, num_two)
+  return num_one - num_two
+end
+
+def multiply(num_one, num_two)
+  return num_one * num_two
+end
+
+def divide(num_one, num_two)
+  return num_one / num_two
+end
+
+# the result value will be printed based on operation user input and two numbers input
+if operation == "add" || operation == "+"
+  puts "\n#{num1} + #{num2} = #{add(num1, num2)}"
+elsif operation == "subtract" || operation == "-"
+  puts "\n#{num1} - #{num2} = #{subtract(num1, num2)}"
+elsif operation == "multiply" || operation == "*"
+  puts "\n#{num1} * #{num2} = #{multiply(num1, num2)}"
+elsif operation == "divide" || operation == "/"
+  puts "\n#{num1} / #{num2} = #{divide(num1, num2)}"
+else
+  puts "error"
+end