OverflowException Class (System)

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.

  Visual Basic

  
  Dim value As Integer = 780000000
  Try
     ' Square the original value.
     Dim square As Integer = value * value 
     Console.WriteLine("{0} ^ 3 = {1}", value, square)
  Catch e As OverflowException
     Dim square As Double = Math.Pow(value, 2)
     Console.WriteLine("Exception: {0} > {1:E}.", _
                       square, Int32.MaxValue)
  End Try
  ' The example displays the following output:
  '       Exception: 6.084E+17 > 2.147484E+009.
  
  
  

  C#

  
  int value = 780000000;
  checked {
  try {
     // Square the original value.
     int square = value * value; 
     Console.WriteLine("{0} ^ 3 = {1}", value, square);
  }
  catch (OverflowException) {
     double square = Math.Pow(value, 2);
     Console.WriteLine("Exception: {0} > {1:E}.", 
                       square, Int32.MaxValue);
  } }
  // The example displays the following output:
  //       Exception: 6.084E+17 > 2.147484E+009.
  
  
  

• 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.

  Visual Basic

  
  Dim value As Byte = 241
  Try
     Dim newValue As SByte = (CSByte(value))
     Console.WriteLine("Converted the {0} value {1} to the {2} value {3}.", _
                       value.GetType().Name, value, _
                       newValue.GetType().Name, newValue)
  Catch e As OverflowException
     Console.WriteLine("Exception: {0} > {1}.", value, SByte.MaxValue)
  End Try                            
  ' The example displays the following output:
  '       Exception: 241 > 127.
  
  
  

  C#

  
  byte value = 241;
  checked {
  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:
  //       Exception: 241 > 127.
  
  
  

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.

.NET Framework

.NET Framework Client Profile

Portable Class Library

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

Other Resources