Enumerable.Sum(TSource) Method (IEnumerable(TSource), Func(TSource, Nullable(Single)))
Computes the sum of the sequence of nullable Single 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)
Type Parameters
- TSource
The type of the elements of source.
Parameters
- source
- Type: System.Collections.Generic.IEnumerable(TSource)
A sequence of values that are used to calculate a sum.
- selector
- Type: System.Func(TSource, Nullable(Single))
A transform function to apply to each element.
Usage Note
In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable(TSource). When you use instance method syntax to call this method, omit the first parameter.| Exception | Condition |
|---|---|
| ArgumentNullException | source or selector is a null reference (Nothing in Visual Basic). |
This method returns zero if source contains no elements.
The result does not include values that are a null reference (Nothing in Visual Basic).
You can apply this method to a sequence of arbitrary values if you provide a function, selector, that projects the members of source into a numeric type, specifically Nullable<Single> in C# or Nullable(Of Single) in Visual Basic.
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(TSource)(IEnumerable(TSource), Func(TSource, Double)) to sum the projected values of a sequence.
Note: |
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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. |
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.
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