TechNet
Export (0) Print
Expand All

Enumerable.Average<TSource> Method (IEnumerable<TSource>, Func<TSource, Nullable<Int64>>)

 

Computes the average of a sequence of nullable Int64 values that are obtained by invoking a transform function on each element of the input sequence.

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

public static Nullable<double> Average<TSource>(
	this IEnumerable<TSource> source,
	Func<TSource, Nullable<long>> selector
)

Parameters

source
Type: System.Collections.Generic.IEnumerable<TSource>

A sequence of values to calculate the average of.

selector
Type: System.Func<TSource, Nullable<Int64>>

A transform function to apply to each element.

Return Value

Type: System.Nullable<Double>

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

Type Parameters

TSource

The type of the elements of source.

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, Int64>) to calculate an average.

System_CAPS_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.

string[] numbers = { "10007", "37", "299846234235" };

double average = numbers.Average(num => Convert.ToInt64(num));

Console.WriteLine("The average is {0}.", average);

// This code produces the following output:
//
// The average is 99948748093. 

Universal Windows Platform
Available since 4.5
.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
Return to top
Show:
© 2016 Microsoft