Enumerable.Average Method (IEnumerable(Of Nullable(Of Double)))


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Computes the average of a sequence of nullable Double values.

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

Public Shared Function Average (
	source As IEnumerable(Of Nullable(Of Double))
) As Nullable(Of Double)


Type: System.Collections.Generic.IEnumerable(Of Nullable(Of Double))

A sequence of nullable Double values to calculate the average of.

Return Value

Type: System.Nullable(Of Double)

The average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

Exception Condition

source is null.

If the sum of the elements is too large to represent as a Double, this method returns positive or negative infinity.

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

The following code example demonstrates how to use Average(IEnumerable(Of Nullable(Of Int64))) to calculate an average.


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 long values.
Dim longs() As Nullable(Of Long) = {Nothing, 10007L, 37L, 399846234235L}

' Determine the average value in the array.
Dim avg As Nullable(Of Double) = longs.Average()

' Display the output.
MsgBox("The average is " & avg.ToString)

' This code produces the following output:
' The average is 133282081426.333

Universal Windows Platform
Available since 8
.NET Framework
Available since 3.5
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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