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OverflowException Class

Updated: April 2009

The exception that is thrown when an arithmetic, casting, or conversion operation in a checked context results in an overflow.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

public class OverflowException extends ArithmeticException

An OverflowException is thrown at run time under the following conditions:

  • An arithmetic operation produces a result that is outside the range of the data type returned by the operation. The following example illustrates the OverflowException that is thrown by a multiplication operation that overflows the bounds of the Int32 type.

    No code example is currently available or this language may not be supported.
  • A casting or conversion operation attempts to perform a narrowing conversion, and the value of the source data type is outside the range of the target data type. The following example illustrates the OverflowException that is thrown by the attempt to convert a large unsigned byte value to a signed byte value.

    No code example is currently available or this language may not be supported.

In each case, the result of the operation is a value that is less than the MinValue property or greater than the MaxValue property of the data type that results from the operation.

For the arithmetic, casting, or conversion operation to throw an OverflowException, the operation must occur in a checked context. By default, arithmetic operations and overflows in Visual Basic are checked; in C#, they are not. If the operation occurs in an unchecked context, the result is truncated by discarding any high-order bits that do not fit into the destination type. The following example illustrates such an unchecked conversion in C#. It repeats the previous example in an unchecked context.

byte value = 241;
try {
   sbyte newValue = (sbyte) value;
   Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", 
                     value.GetType().Name, value, 
                     newValue.GetType().Name, newValue);
catch (OverflowException) {
   Console.WriteLine("Exception: {0} > {1}.", value, SByte.MaxValue);
// The example displays the following output: 
//       Converted the Byte value 241 to the SByte value -15.

The following Microsoft intermediate language (MSIL) instructions throw an OverflowException:

  • add.ovf.<signed>

  • conv.ovf.<to type>

  • conv.ovf.<to type>.un

  • mul.ovf.<type>

  • sub.ovf.<type>

  • newarr

OverflowException uses the HRESULT COR_E_OVERFLOW, which has the value 0x80131516.

For a list of initial property values for an instance of OverflowException, see the OverflowException constructors.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0

XNA Framework

Supported in: 3.0, 2.0, 1.0




April 2009

Expanded the Remarks section.

Customer feedback.