Exception in C#

CsharpServer Side ProgrammingProgramming

An exception is a problem that arises during the execution of a program. A C# exception is a response to an exceptional circumstance that arises while a program is running, such as an attempt to divide by zero.

Exceptions provide a way to transfer control from one part of a program to another. C# exception handling is built upon four keywords −

  • try − A try block identifies a block of code for which particular exceptions are activated. It is followed by one or more catch blocks.

  • catch − A program catches an exception with an exception handler at the place in a program where you want to handle the problem. The catch keyword indicates the catching of an exception.

  • finally − The finally block is used to execute a given set of statements, whether an exception is thrown or not thrown. For example, if you open a file, it must be closed whether an exception is raised or not.

  • throw − A program throws an exception when a problem shows up. This is done using a throw keyword.

C# exceptions are represented by classes. The exception classes in C# are mainly directly or indirectly derived from the System. Exception class. Some of the exception classes derived from the System. The exception class is the System.ApplicationException and System.SystemException classes.

Example

Let us see an example −

 Live Demo

using System;
using System.Reflection;
public class Demo {
   public static void Main(){
      Type type = typeof(Subject);
      try {
         FieldInfo fieldInfo = type.GetField("SubName");
         MemberInfo[] info = type.GetMember("SubName");
         Console.Write("Members = ");
         for (int i = 0; i < info.Length; i++)
            Console.WriteLine(" {0}", info[i]);
         Console.WriteLine("FieldInfo = {0}", fieldInfo);
      }
      catch (ArgumentNullException e){
         Console.Write("{0}", e.GetType(), e.Message);
      }
   }
}
public class Subject{
   public string SubName = "Science";
}

Output

This will produce the following output −

Members = System.String SubName
FieldInfo = System.String SubName

Example

Let us now see another example −

 Live Demo

using System;
public class Demo {
   int result;
   Demo() {
      result = 0;
   }
   public void division(int num1, int num2) {
      try {
         result = num1 / num2;
      }
      catch (DivideByZeroException e) {
         Console.WriteLine("Exception caught = {0}", e);
      }
      finally {
         Console.WriteLine("Result = {0}", result);
      }
   }
   public static void Main(string[] args) {
      Demo d = new Demo();
      d.division(100, 0);
   }
}

Output

This will produce the following output −

Exception caught = System.DivideByZeroException: Attempted to divide by zero.
   at Demo.division(Int32 num1, Int32 num2) in d:\Windows\Temp\n0kebv45.0.cs:line 11 
Result = 0
raja
Published on 11-Dec-2019 07:17:52

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