Enumerable.Sum Method (IEnumerable<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)
Syntax
'Declaration
<ExtensionAttribute> _
Public Shared Function Sum ( _
source As IEnumerable(Of Nullable(Of Single)) _
) As Nullable(Of Single)
public static Nullable<float> Sum(
this IEnumerable<Nullable<float>> source
)
Parameters
- 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.
Exceptions
| Exception | Condition |
|---|---|
| ArgumentNullException | source is nulla null reference (Nothing in Visual Basic). |
Remarks
This method returns zero if source contains no elements.
The result does not include values that are nulla null reference (Nothing in Visual Basic).
In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.
Examples
The following code example demonstrates how to use Sum(IEnumerable<Nullable<Single>>) to sum the values of a sequence.
' Create an array of Nullable Single values.
Dim points() As Nullable(Of Single) = _
{Nothing, 0, 92.83F, Nothing, 100.0F, 37.46F, 81.1F}
' Get the sum of values in the list.
Dim sum As Nullable(Of Single) = points.Sum()
' Display the output.
outputBlock.Text &= "Total points earned: " & sum & vbCrLf
' This code produces the following output:
'
' Total points earned: 311.39
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
*/
Version Information
Silverlight
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
Platforms
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.