Queryable.Sum Method (IQueryable<Nullable<Single>>)


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Computes the sum of a sequence of nullable Single values.

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

public static Nullable<float> Sum(
	this IQueryable<Nullable<float>> source


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

A sequence of nullable Single values to calculate the sum of.

Return Value

Type: System.Nullable<Single>

The sum of the values in the sequence.

Exception Condition

source is null.

The Sum(IQueryable<Nullable<Single>>) method generates a MethodCallExpression that represents calling Sum(IQueryable<Nullable<Single>>) itself as a constructed generic method. 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 Sum(IQueryable<Nullable<Single>>) depends on the implementation of the type of the source parameter. The expected behavior is that it returns the sum of the values in source.

The following code example demonstrates how to use Sum(IQueryable<Nullable<Single>>) to sum the values of a sequence.

float?[] points = { null, 0, 92.83F, null, 100.0F, 37.46F, 81.1F };

float? sum = points.AsQueryable().Sum();

Console.WriteLine("Total points earned: {0}", sum);

    This code produces the following output:

    Total points earned: 311.39

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 7.1
Windows Phone
Available since 8.1
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