C# C# Basics (Retired) Perfect Wrap Up

Cody Smith
Cody Smith
4,510 Points

Returning the program to where it threw an acception

I'm trying to do the Arithmetic Calculator Practice Project in C#. Below is what I've come up with:

using System;

namespace Treehouse.Calculator { class Calculator { static void Main() {

  bool calculator = true;

  while (calculator)
  {
    //Prompt user to enter the first number in their calculation
    Console.Write("Enter the first number in your operation: ");
    string entry1 = Console.ReadLine();
    if(entry1.ToLower () == "quit")
    {
      return;
    }
    else
    {
      try
      {
      double number1 = double.Parse(entry1);

      //Prompt user to enter an operation
      Console.Write("Enter an operator ( +, -, *, or /): ");
      string sign = Console.ReadLine();
      if(sign == "quit")
      {
        return; 
      }
      else
      {
        //Promt user for another number
        Console.Write("Enter the second number: ");
        string entry2 = Console.ReadLine();
        double number2 = double.Parse(entry2);
        if(entry2 == "quit")
        {
          return;
        }
        else
        {
          //Print results to the screen
            if(sign == "+")
            {
              Console.WriteLine(number1 + " + " + number2 + " = " + (number1 + number2));
            }
            else if(sign == "-")
            {
              Console.WriteLine(number1 + " - " + number2 + " = " + (number1 - number2));
            }
            else if(sign == "*")
            {
              Console.WriteLine(number1 + " * " + number2 + " = " + (number1 * number2));
            }
            else if(sign == "/")
            {
              Console.WriteLine(number1 + " / " + number2 + " = " + (number1 / number2));
            }
        }   
      }
     }
      catch(FormatException)
      {
        Console.WriteLine("That is not valid input.");
        continue;
      }
    }
     //Repeat until the user types "quit" at any of the prompts.
     Console.WriteLine("Goodbye");
  }
}

} }

Two things: 1) When you enter an invalid character into any of the questions, it will tell me "That is not a valid input" and return me to the first question. I want it to return to the question that you entered the incorrect info on. So if on question 2 "Enter an operator ( +, -, *, or /): " I entered hi, it would say "That is not valid input." and return to that question.

2) What can be cleaned up to make it look cleaner. It's looking long and bulky.

Thanks!

1 Answer

Steven Parker
Steven Parker
173,989 Points

To prevent starting completely over on an error, you could have a separate retry loop with it's own "try" and "catch" for each question.

And to make the code more compact, you could look for places where similar things are done more than once and create and call a function to do them. Prompting for and inputting a number might be a possible candidate.