throw (C# Reference)

The thrown exception is an object whose class is derived from System.Exception, for example:

class MyException : System.Exception {}
// ...
throw new MyException();

Usually the throw statement is used with try-catch or try-finally statements. When an exception is thrown, the program looks for the catch statement that handles this exception.

You can also rethrow a caught exception using the throw statement. For more information and examples, see try-catch and Throwing Exceptions.

This example demonstrates how to throw an exception using the throw statement.

// throw example
using System;
public class ThrowTest 
{
    static void Main() 
    {
        string s = null;

        if (s == null) 
        {
            throw new ArgumentNullException();
        }

        Console.Write("The string s is null"); // not executed
    }
}

The ArgumentNullException exception occurs.

See the try-catch, try-finally, and try-catch-finally examples.

For more information, see the following sections in the C# Language Specification:

• 5.3.3.11 Throw statements

• 8.9.5 The throw statement

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