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Queryable.Sum Method (IQueryable(Of Nullable(Of Single)))

.NET Framework 4.5

Computes the sum of a sequence of nullable Single values.

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

'Declaration
<ExtensionAttribute> _
Public Shared Function Sum ( _
	source As IQueryable(Of Nullable(Of Single)) _
) As Nullable(Of Single)

Parameters

source: Type: System.Linq.IQueryable(Of Nullable(Of Single))
A sequence of nullable Single values to calculate the sum of.

Return Value

Type: System.Nullable(Of Single)
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 IQueryable(Of Nullable(Of Single)). 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

Exception	Condition
ArgumentNullException	source is Nothing.

Remarks

The Sum(IQueryable(Of Nullable(Of Single))) method generates a MethodCallExpression that represents calling Sum(IQueryable(Of Nullable(Of Single))) itself as a constructed generic method. It then passes the MethodCallExpression to the Execute(Of TResult)(Expression) method of the IQueryProvider represented by the Provider property of the source parameter.

The query behavior that occurs as a result of executing an expression tree that represents calling Sum(IQueryable(Of Nullable(Of Single))) depends on the implementation of the type of the source parameter. The expected behavior is that it returns the sum of the values in source.

Examples

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

Dim points As Nullable(Of Single)() = {Nothing, 0, 92.83F, Nothing, 100.0F, 37.46F, 81.1F}

        Dim sum As Nullable(Of Single) = points.AsQueryable().Sum()

        MsgBox("Total points earned: " & sum)

        'This code produces the following output: 

        'Total points earned: 311.39

Version Information

.NET Framework

Supported in: 4.5, 4, 3.5

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

Platforms

Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

Reference

Queryable Class

Sum Overload

System.Linq Namespace

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