# Enumerable.Sum(TSource) Method (IEnumerable(TSource), Func(TSource, Decimal))

.NET Framework 4.5

Computes the sum of the sequence of Decimal values that are obtained by invoking a transform function on each element of the input sequence.

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

## Syntax

```static member Sum :
source:IEnumerable<'TSource> *
selector:Func<'TSource, decimal> -> decimal
```

#### 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, Decimal)

A transform function to apply to each element.

#### Return Value

Type: System.Decimal
The sum of the projected values.

#### 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).

## Exceptions

ExceptionCondition
ArgumentNullException

source or selector is a null reference (Nothing in Visual Basic).

OverflowException

The sum is larger than MaxValue.

## Remarks

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 Decimal.

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(TSource)(IEnumerable(TSource), Func(TSource, Double)) to sum the projected values of a sequence.

Note

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.

No code example is currently available or this language may not be supported.

## Version Information

#### .NET Framework

Supported in: 4.6, 4.5, 4, 3.5

#### .NET Framework Client Profile

Supported in: 4, 3.5 SP1

#### XNA Framework

Supported in: 3.0

#### Portable Class Library

Supported in: Portable Class Library
Supported in: Windows Phone 8.1
Supported in: Windows Phone Silverlight 8.1
Supported in: Windows Phone Silverlight 8