Enumerable.Sum Method (IEnumerable<Nullable<Single>>)

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 IEnumerable<Nullable<float>> source


Type: System.Collections.Generic.IEnumerable<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.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable<Nullable<Single>>. When you use instance method syntax to call this method, omit the first parameter.


source is null.

This method returns zero if source contains no elements.

The result does not include values that are null.

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

The following code example demonstrates how to use Sum(IEnumerable<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.Sum();

      outputBlock.Text += String.Format("Total points earned: {0}", sum) + "\n";

       This code produces the following output:

       Total points earned: 311.39


Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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