Enumerable::Sum<TSource> Method (IEnumerable<TSource>, Func<TSource, Double>)
Computes the sum of the sequence of Double 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)
[ExtensionAttribute] public: generic<typename TSource> static double Sum( IEnumerable<TSource>^ source, Func<TSource, double>^ selector )
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, Double>
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. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).| Exception | Condition |
|---|---|
| ArgumentNullException | source or selector is nullptr. |
This method returns zero if source contains no elements.
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 Double.
In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
