Part 44 - C# Tutorial - Preventing exception handling abuse

In Part 43, we have seen what, Exception Handling Abuse is all about. If you haven't watched that video, please click here to watch it now.


In this session we will learn how to prevent exception handling abuse, by rewriting the program, that we have started in Part 43.

Part 44 - C# Tutorial - Preventing exception handling abuse

Rewritten example that doesn't use exception handling to control program's logical flow.
using System;
public class ExceptionHandlingAbuse
{
    public static void Main()
    {
        try
        {
            Console.WriteLine("Please enter Numerator");
            int Numerator;
            //int.TryParse() will not throw an exception, instead returns false
            //if the entered value cannot be converted to integer
            bool isValidNumerator = int.TryParse(Console.ReadLine(), out Numerator);


            if (isValidNumerator)
            {
                Console.WriteLine("Please enter Denominator");
                int Denominator;
                bool isValidDenominator = int.TryParse(Console.ReadLine(), out Denominator);


                if (isValidDenominator && Denominator != 0)
                {
                    int Result = Numerator / Denominator;
                    Console.WriteLine("Result = {0}", Result);
                }
                else
                {
                    //Check if the denominator is zero and print a friendly error
                    //message instead of allowing DivideByZeroException exception 
                    //to be thrown and then printing error message to the user.
                    if (isValidDenominator && Denominator == 0)
                    {
                        Console.WriteLine("Denominator cannot be zero");
                    }
                    else
                    {
                        Console.WriteLine("Only numbers between {0} && {1} are allowed",
                            Int32.MinValue, Int32.MaxValue);
                    }
                }
            }
            else
            {
                Console.WriteLine("Only numbers between {0} && {1} are allowed",
                            Int32.MinValue, Int32.MaxValue);
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
    }
}