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Queryable.Average Method (IQueryable<Nullable<Decimal>>)


Computes the average of a sequence of nullable Decimal values.

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

public static Nullable<decimal> Average(
	this IQueryable<Nullable<decimal>> source


Type: System.Linq.IQueryable<Nullable<Decimal>>

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

Return Value

Type: System.Nullable<Decimal>

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

Exception Condition

source is null.

The Average(IQueryable<Nullable<Decimal>>) method generates a MethodCallExpression that represents calling Average(IQueryable<Nullable<Decimal>>) itself. It then passes the MethodCallExpression to the Execute<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 Average(IQueryable<Nullable<Decimal>>) depends on the implementation of the type of the source parameter. The expected behavior is that it calculates the average of the values in source.

The following code example demonstrates how to use Average(IQueryable<Nullable<Int64>>) to calculate the average of a sequence of values.


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.

long?[] longs = { null, 10007L, 37L, 399846234235L };

double? average = longs.AsQueryable().Average();

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

// This code produces the following output:
// The average is 133282081426.333. 

Universal Windows Platform
Available since 4.5
.NET Framework
Available since 3.5
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.1
Windows Phone
Available since 8.1
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