Queues - Anna Barklund - Create calculator.rb

calculator.rb

@@ -0,0 +1,98 @@
+# Method for checking if a valid number is entered
+# If a valid number is entered it is converted from string
+# to integer if it was entered as an integer
+# to float if it was entered as a float
+def check_number( num )
+  if num.to_f != 0 || ["0", "0.0"].include?(num)
+    is_float = false
+    if num.include? "."
+      is_float = true
+    end
+    if is_float
+      as_number = num.to_f
+    else
+      as_number = num.to_i
+    end
+    return {number_ok: true, as_number: as_number}
+  else
+    return {number_ok: false}
+  end
+end
+
+# Method for addition
+def adding( num1, num2 )
+  return [num1 + num2, "+"]
+end
+
+# Method for subtraction
+def subtracting( num1, num2 )
+  return [num1 - num2, "-"]
+end
+
+# Method for multiplication
+def multiplying( num1, num2 )
+  return [num1 * num2, "*"]
+end
+
+# Method for division
+def dividing( num1, num2 )
+  return [num1 / num2, "/"]
+end
+
+operands = ["add", "+",
+  "subtract", "-",
+  "multiply", "*",
+  "divide", "/"
+]
+
+puts "\nThis is a calculator that can handle addition, subtraction, multiplication or division of two numbers\n\n"
+
+
+# Input
+inputs_ok = false
+until inputs_ok
+  # Entering of operand and numbers
+  puts "Please enter your choice of operand."
+  puts "You can choose between: "
+  puts operands.join(", ")
+  print "\nYour choice: "
+  operand_input = gets.chomp
+  print "Please enter the first number: "
+  num1_input = gets.chomp
+  print "Please enter the second number: "
+  num2_input = gets.chomp
+
+  # Checking operand and numbers
+  operand_ok = operands.include?(operand_input)
+  num1 = check_number(num1_input)
+  num2 = check_number(num2_input)
+
+  # If operand and numbers all are ok, exit the until-loop
+  if operand_ok && num1[:number_ok] && num2[:number_ok]
+    # Handling of division by zero
+    if ["divide", "/"].include?(operand_input) && num2[:as_number] == 0
+      puts "\nOps, you are trying to divide #{num1[:as_number]} by zero."
+      puts "Please start over.\n\n"
+    else
+      inputs_ok = true # All ok
+    end
+  else
+    puts "\nOps, something was not entered right."
+    puts "Make another try! (Please see to that you enter the right type of operand and that you enter the numbers properly.)\n\n"
+  end
+
+end # the until-loop end
+
+
+# Choice of method depending on the users choice of operand
+case operand_input
+when "add", "+" then result = adding(num1[:as_number], num2[:as_number])
+when "subtract", "-" then result = subtracting(num1[:as_number], num2[:as_number])
+when "multiply", "*" then result = multiplying(num1[:as_number], num2[:as_number])
+when "divide", "/" then result = dividing(num1[:as_number], num2[:as_number])
+end
+
+
+# Printing the result to the terminal
+puts "\nThe result is: #{result[0]}"
+puts "#{num1[:as_number]} #{result[1]} #{num2[:as_number]} = #{result[0]}\n\n"