throw (C# Reference)

The throw statement is used to signal the occurrence of an anomalous situation (exception) during the program execution.

Remarks

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.

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

Example

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

public class ThrowTest2
{

    static int GetNumber(int index)
    {
        int[] nums = { 300, 600, 900 };
        if (index > nums.Length)
        {
            throw new IndexOutOfRangeException();
        }
        return nums[index];

    }
    static void Main() 
    {
        int result = GetNumber(3);

    }
}
/*
    Output:
    The System.IndexOutOfRangeException exception occurs.
*/

Code Example

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

C# Language Specification

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

• 5.3.3.11 Throw statements

• 8.9.5 The throw statement

See Also

Tasks

How to: Explicitly Throw Exceptions

Concepts

C# Programming Guide

Reference

The try, catch, and throw Statements

C# Keywords

Exception Handling Statements (C# Reference)

Other Resources

C# Reference

Change History

Date	History	Reason
September 2008	Fixed example code.	Customer feedback.