C# Systemexception Class

The SystemException is a predefined exception class in the C# programming language. It is used to handle system-related exceptions. It works as a base class for the system exception namespace. The SystemException class is used to represent errors that occur during program execution and are thrown by the Common Language Runtime (CLR).

In the C# programming language , most of the built-in exceptions (such as IndexOutOfRangeException, NullReferenceException, InvalidCastException, etc.) are derived from the SystemException.

Syntax:

It has the following syntax:

[SerializableAttribute]  

[ComVisibleAttribute(true)]  

public class SystemException : Exception

C# SystemException Class Example

Let us take an example to illustrate the SystemException class in C#.

Example

using System;  

namespace CSharpProgram  

{  

    class Program  

    {  

        static void Main(string[] args)  

        {  

            try  

            {  

                int[] arr = new int[5];  

                arr[10] = 25;  

            }  

            catch (SystemException e)  

            {  

                Console.WriteLine(e);  

            }  

        }  

    }  

}

Output:

System.IndexOutOfRangeException: Index was outside the bounds of the array.

Explanation:

In this example, we have taken an array of size 5, but the code tries to access index 10, which is out of range. After that, it causes a System.IndexOutOfRangeException, which is a subclass of SystemException, is caught in the catch block where the exception details are displayed.

Important Points about SystemException in C#

Several important points about SystemException in C# are as follows:

• ✅ It represents the base class for all exceptions that are thrown by the runtime environment.
• ✅ It offers standard constructors and properties to access error details, such as message, stack trace, and many inner exceptions.
• ✅ It is not compulsory to create our own custom exceptions from SystemException. Instead, we can create them directly from Exception.

SystemExceptions consists of rich constructors, properties, and methods that we have tabulated below.

C# SystemException Constructors

The table below shows several types of SystemException constructors in C#.

C# SystemException Properties

The table below shows several types of SystemException properties in C#.

C# SystemException Methods

The table below shows several types of SystemException methods in C#.

C# SystemException Example using Catching Specific Exception

Let us take an example to illustrate the System Exception by catching a specific exception in C.

Example

using System;

class C# Tutorial

{

    static void Main()

    {

        try

        {

            string str = null;

            Console.WriteLine(str.Length); // NullReferenceException

        }

        catch (NullReferenceException ex)

        {

            Console.WriteLine("Caught a NullReferenceException: " + ex.Message);

        }

        catch (SystemException ex)

        {

            Console.WriteLine("Caught another SystemException: " + ex.Message);

        }

    }

}

Output:

Caught a NullReferenceException: Object reference not set to an instance of an object

Explanation:

In this example, we try to access the Length property of a null string, which throws a NullReferenceException. First, we use the catch block that handles it specifically, while the second catch is used for SystemException that would handle any other system-level exceptions if they occurred.

Conclusion

In conclusion, the SystemException class is an important class that acts as the base for all runtime exceptions that are thrown by the Common Language Runtime (CLR) . If we do not use it to throw exceptions directly, it gives a method to find multiple runtime errors. It is commonly used in specific exceptions, which provides better error handling and debugging.

SystemException FAQs

1) What is SystemException in C#?

In the C# programming language, the SystemException is a base class that is used for all predefined exceptions in .NET, which can occur during program execution.

2) What are the common exceptions derived from SystemException in C#?

In C#, there are several exceptions derived from SystemException. Some of them are as follows:

• ✅ NullReferenceException
• ✅ IndexOutOfRangeException
• ✅ InvalidCastException
• ✅ OutOfMemoryException

3) Can we directly use the SystemException in catch blocks in C#?

Yes, we can directly use the SystemException in catch blocks in C#. However, it is usually recommended to find more specific exceptions, such as NullReferenceException or IndexOutOfRangeException.

4) Where can we define SystemException in C#?

In C#, we can define the SystemException in the System namespace within the mscorlib.dll assembly.

5) Can we throw SystemException manually in our code in C#?

No, we cannot throw SystemException directly in C#. However, we can throw specific exception types or create custom exceptions.