Space - Sara Nilsen

sara_nilsen.rb

@@ -0,0 +1,66 @@
+puts "Welcome to the Calculator program! Which operator would you like to use? (add(+), substract(-), multiply(*), divide(/) or exponify(**)."
+
+puts "Please choose one operator(name or symbol):"
+operator_user = gets.chomp.downcase 
+
+until ["add", "+", "subtract", "-", "multiply", "*", "divide", "/", "%", "exponify", "**"].include?(operator_user)
+    puts "Please tell me to add (+), subtract (-), multiply (*), divide (/) or exponify (**)!"
+    operator_user = gets.chomp.downcase
+end
+
+def float_or_integer(num)
+    num % 1.0 == 0 ? num.to_i : num.to_f 
+end 
+
+def is_number?(string)
+    true if Float(string) rescue false 
+end
+
+puts "Please enter a number:"
+first_num = gets.chomp 
+
+until is_number?(first_num)
+    puts "Please re-enter a valid number:"
+    first_num = gets.chomp 
+end 
+
+first_num = first_num.to_f
+
+puts "Please enter a second number:"
+sec_num = gets.chomp 
+
+until is_number?(sec_num)
+    puts "Please re-enter a valid number:"
+    sec_num = gets.chomp 
+end 
+sec_num = sec_num.to_f
+
+total = 0 
+
+case operator_user
+when "add", "+"
+    total = first_num + sec_num 
+    operator_user = "+"
+when "subtract", "-"
+    total = first_num - sec_num
+    operator_user = "-" 
+when "multiply", "*"
+    total = first_num * sec_num 
+    operator_user = "*"
+when "divide", "/", "%"
+    if sec_num == 0
+        puts "Please enter a number greater than 0"
+        sec_num = gets.chomp.to_f
+        until sec_num > 0 
+            sec_num = gets.chomp.to_f
+        end 
+    end
+    total = first_num / sec_num 
+    operator_user = "/" 
+when "exponify", "**"
+    total = first_num ** sec_num 
+    operator_user = "**"
+end
+
+puts "Your result is #{float_or_integer(first_num)} #{operator_user} #{float_or_integer(sec_num)} = #{float_or_integer(total)}"
+