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MSDN Library

Enumerable.Average(TSource) Method (IEnumerable(TSource), Func(TSource, Single))

Computes the average of a sequence of Single values that are obtained by invoking a transform function on each element of the input sequence.

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

static member Average : 
        source:IEnumerable<'TSource> * 
        selector:Func<'TSource, float32> -> float32

Type Parameters

TSource

The type of the elements of source.

Parameters

source
Type: System.Collections.Generic.IEnumerable(TSource)

A sequence of values to calculate the average of.

selector
Type: System.Func(TSource, Single)

A transform function to apply to each element.

Return Value

Type: System.Single
The average of the sequence of values.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable(TSource). 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).

ExceptionCondition
ArgumentNullException

source or selector is a null reference (Nothing in Visual Basic).

InvalidOperationException

source contains no elements.

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(TSource)(IEnumerable(TSource), Func(TSource, Int32)) to calculate an average.

NoteNote

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, change the body of the selector function.

No code example is currently available or this language may not be supported.

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Portable Class Library

Supported in: Portable Class Library
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