# Enumerable.Average Method (IEnumerable(Of Nullable(Of Int32)))

.NET Framework (current version)

Computes the average of a sequence of nullable Int32 values.

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

## Syntax

```<ExtensionAttribute>
Public Shared Function Average (
source As IEnumerable(Of Nullable(Of Integer))
) As Nullable(Of Double)
```

#### Parameters

source
Type:

A sequence of nullable Int32 values to calculate the average of.

#### Return Value

Type:

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

## Exceptions

Exception Condition
ArgumentNullException

source is null.

OverflowException

The sum of the elements in the sequence is larger than MaxValue.

## Remarks

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

## Examples

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

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 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

```

## Version Information

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