# Enumerable.Sum Method (IEnumerable(Of Nullable(Of Decimal)))

.NET Framework 3.5

Computes the sum of a sequence of nullable Decimal values.

Namespace:  System.Linq
Assembly:  System.Core (in System.Core.dll)

## Syntax

```'Declaration
<ExtensionAttribute> _
Public Shared Function Sum ( _
source As IEnumerable(Of Nullable(Of Decimal)) _
) As Nullable(Of Decimal)
'Usage
Dim source As IEnumerable(Of Nullable(Of Decimal))
Dim returnValue As Nullable(Of Decimal)

returnValue = source.Sum()
```

#### Parameters

source
Type: System.Collections.Generic.IEnumerable(Of Nullable(Of Decimal))

A sequence of nullable Decimal values to calculate the sum of.

#### Return Value

Type: System.Nullable(Of Decimal)
The sum of the values in the sequence.

#### Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable(Of Nullable(Of Decimal)). When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).

## Exceptions

ExceptionCondition
ArgumentNullException

source is Nothing.

OverflowException

The sum is larger than MaxValue.

## Remarks

This method returns zero if source contains no elements.

The result does not include values that are Nothing.

In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

## Examples

The following code example demonstrates how to use Sum(IEnumerable(Of Nullable(Of Single))) to sum the values of a sequence.

Note:

This code example uses an overload of this overloaded method that is different from the specific overload that this topic describes. To extend the example to this topic, substitute the elements of the source sequence with elements of the appropriate numerical type.

```' Create an array of Nullable Single values.
Dim points() As Nullable(Of Single) = _
{Nothing, 0, 92.83F, Nothing, 100.0F, 37.46F, 81.1F}

' Get the sum of values in the list.
Dim sum As Nullable(Of Single) = points.Sum()

' Display the output.
MsgBox("Total points earned: " & sum)

' This code produces the following output:
'
' Total points earned: 311.39
```

## Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, 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.

## Version Information

#### .NET Framework

Supported in: 3.5

#### .NET Compact Framework

Supported in: 3.5

#### XNA Framework

Supported in: 3.0