C# User-Defined Exceptions

C# allows us to create user-defined or custom exception. It is used to make the meaningful exception. To do this, we need to inherit Exception class.

C# user-defined exception example

1. using System;  
2. public class InvalidAgeException : Exception  
3. {  
4.     public InvalidAgeException(String message)  
5.         : base(message)  
6.     {  
7.   
8.     }  
9. }  
10. public class TestUserDefinedException  
11. {  
12.     static void validate(int age)  
13.     {  
14.         if (age < 18)  
15.         {  
16.             throw new InvalidAgeException("Sorry, Age must be greater than 18");  
17.         }  
18.     }  
19.     public static void Main(string[] args)  
20.     {  
21.         try  
22.         {  
23.             validate(12);  
24.         }  
25.         catch (InvalidAgeException e) { Console.WriteLine(e); }  
26.         Console.WriteLine("Rest of the code");  
27.     }  
28. }  

Output:

InvalidAgeException: Sorry, Age must be greater than 18
Rest of the code