C# Exception Handling : try-catch-finally Statement

Updated on September 21, 2015     Kisan Patel

In C#, Exception is a run-time error that arises because of some abnormal conditions, such as a division of a number by zero, passing a string to a variable that holds an integer value.

Difference between Run time and Compile time errors

Compile time errors are those errors that occur during compilation of a program. It can happen due to bad coding or incorrect syntax. You can correct these compile time errors after looking at the error message that the compiler generates.

Run time errors are those errors that occur during execution of a program and thus at that time they cannot be corrected. So you can handle those errors, when they occur by using try…catch statement.

The try…catch Statement

C# provides the try…catch statement for exception handling. The try block encloses those statements that can cause an error; whereas, the catch block encloses the statements to handle the exception, it it occurs.

For Example,

using System;

namespace ConsoleApp
{
    class Program
    {
        static void Main(string[] args)
        {
            int number = 0;
            int p = 0;

            try
            {
                p = 100 / number;
            }
            catch (DivideByZeroException e)
            {
                Console.WriteLine("Exception Occured!");
            }
        }
    }
}

the above C# code will produce below output…

In above code, when 100 is divided by 0, the DivideByZeroException occurs; and therefore, the program control is transferred to the catch block and executes the statement inside the catch block.

You can also use finally with try…catch block as shown in below code. The statement enclosed inside finally block are always executed, irrespective of the fact whether an exception occurs or not.

try
{
    p = 100 / number;
}
catch (DivideByZeroException e)
{
    Console.WriteLine("Exception Occured!");
}
finally
{
    Console.WriteLine("The finally block executed!");
}

the above code will produce below output…

Exception class

We can also print the Message and Stack Trace of the exception using Message and the StackTrace property of the Exception class.

For Example,

try
{
    p = 100 / number;
}
catch (Exception e)
{
    Console.WriteLine("Message : ");
    Console.WriteLine(e.Message);
    Console.WriteLine("\nStack Trace : ");
    Console.WriteLine(e.StackTrace);
}

the above C# code will produce below output…

Here, Message properties of Exception class describes the exception and StackTrace print out the filename along with its complete path and line number which contains the error for the exception.