Enumerable.Sum Method

Definition

Computes the sum of a sequence of numeric values.

 Sum(IEnumerable) Computes the sum of a sequence of Single values. Sum(IEnumerable>) Computes the sum of a sequence of nullable Int32 values. Sum(IEnumerable>) Computes the sum of a sequence of nullable Single values. Sum(IEnumerable>) Computes the sum of a sequence of nullable Int64 values. Sum(IEnumerable>) Computes the sum of a sequence of nullable Double values. Sum(IEnumerable) Computes the sum of a sequence of Int32 values. Sum(IEnumerable) Computes the sum of a sequence of Int64 values. Sum(IEnumerable) Computes the sum of a sequence of Double values. Sum(IEnumerable) Computes the sum of a sequence of Decimal values. Sum(IEnumerable>) Computes the sum of a sequence of nullable Decimal values. Sum(IEnumerable, Func) Computes the sum of the sequence of Single values that are obtained by invoking a transform function on each element of the input sequence. Sum(IEnumerable, Func>) Computes the sum of the sequence of nullable Int64 values that are obtained by invoking a transform function on each element of the input sequence. Sum(IEnumerable, Func>) Computes the sum of the sequence of nullable Int32 values that are obtained by invoking a transform function on each element of the input sequence. Sum(IEnumerable, Func>) Computes the sum of the sequence of nullable Double values that are obtained by invoking a transform function on each element of the input sequence. Sum(IEnumerable, Func>) 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. Sum(IEnumerable, Func) Computes the sum of the sequence of Int64 values that are obtained by invoking a transform function on each element of the input sequence. Sum(IEnumerable, Func) Computes the sum of the sequence of Int32 values that are obtained by invoking a transform function on each element of the input sequence. Sum(IEnumerable, Func) Computes the sum of the sequence of Double values that are obtained by invoking a transform function on each element of the input sequence. Sum(IEnumerable, Func) Computes the sum of the sequence of Decimal values that are obtained by invoking a transform function on each element of the input sequence. Sum(IEnumerable, Func>) Computes the sum of the sequence of nullable Decimal values that are obtained by invoking a transform function on each element of the input sequence.

Sum(IEnumerable<Single>)

Computes the sum of a sequence of Single values.

``````public:
[System::Runtime::CompilerServices::Extension]
static float Sum(System::Collections::Generic::IEnumerable<float> ^ source);``````
``public static float Sum (this System.Collections.Generic.IEnumerable<float> source);``
``static member Sum : seq<single> -> single``
``````<Extension()>
Public Function Sum (source As IEnumerable(Of Single)) As Single``````

Parameters

source
IEnumerable<Single>

A sequence of Single values to calculate the sum of.

Returns

The sum of the values in the sequence.

Exceptions

`source` is `null`.

Examples

The following code example demonstrates how to use Sum(IEnumerable<Single>) to sum the values of a sequence.

``````List<float> numbers = new List<float> { 43.68F, 1.25F, 583.7F, 6.5F };

float sum = numbers.Sum();

Console.WriteLine("The sum of the numbers is {0}.", sum);

/*
This code produces the following output:

The sum of the numbers is 635.13.
*/
``````
``````' Create a list of Single values.
Dim numbers As New List(Of Single)(New Single() _
{43.68F, 1.25F, 583.7F, 6.5F})

' Get the sum of values in the list.
Dim sum As Single = numbers.Sum()

' Display the output.
Console.WriteLine(\$"The sum of the numbers is {sum}")

' This code produces the following output:
'
' The sum of the numbers is 635.13
``````

Remarks

This method returns zero if `source` contains no elements.

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

Sum(IEnumerable<Nullable<Int32>>)

Computes the sum of a sequence of nullable Int32 values.

``````public:
[System::Runtime::CompilerServices::Extension]
static Nullable<int> Sum(System::Collections::Generic::IEnumerable<Nullable<int>> ^ source);``````
``public static int? Sum (this System.Collections.Generic.IEnumerable<int?> source);``
``static member Sum : seq<Nullable<int>> -> Nullable<int>``
``````<Extension()>
Public Function Sum (source As IEnumerable(Of Nullable(Of Integer))) As Nullable(Of Integer)``````

Parameters

source
IEnumerable<Nullable<Int32>>

A sequence of nullable Int32 values to calculate the sum of.

Returns

The sum of the values in the sequence.

Exceptions

`source` is `null`.

The sum is larger than Int32.MaxValue.

Remarks

Items in `source` that are `null` are excluded from the computation of the sum. This method returns zero if `source` contains no elements or all elements are `null`.

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

Sum(IEnumerable<Nullable<Single>>)

Computes the sum of a sequence of nullable Single values.

``````public:
[System::Runtime::CompilerServices::Extension]
static Nullable<float> Sum(System::Collections::Generic::IEnumerable<Nullable<float>> ^ source);``````
``public static float? Sum (this System.Collections.Generic.IEnumerable<float?> source);``
``static member Sum : seq<Nullable<single>> -> Nullable<single>``
``````<Extension()>
Public Function Sum (source As IEnumerable(Of Nullable(Of Single))) As Nullable(Of Single)``````

Parameters

source
IEnumerable<Nullable<Single>>

A sequence of nullable Single values to calculate the sum of.

Returns

The sum of the values in the sequence.

Exceptions

`source` is `null`.

Examples

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();

Console.WriteLine("Total points earned: {0}", sum);

/*
This code produces the following output:

Total points earned: 311.39
*/
``````
``````' 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.
Console.WriteLine(\$"Total points earned: {sum}")

' This code produces the following output:
'
' Total points earned: 311.39
``````

Remarks

Items in `source` that are `null` are excluded from the computation of the sum. This method returns zero if `source` contains no elements or all elements are `null`.

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

Sum(IEnumerable<Nullable<Int64>>)

Computes the sum of a sequence of nullable Int64 values.

``````public:
[System::Runtime::CompilerServices::Extension]
static Nullable<long> Sum(System::Collections::Generic::IEnumerable<Nullable<long>> ^ source);``````
``public static long? Sum (this System.Collections.Generic.IEnumerable<long?> source);``
``static member Sum : seq<Nullable<int64>> -> Nullable<int64>``
``````<Extension()>
Public Function Sum (source As IEnumerable(Of Nullable(Of Long))) As Nullable(Of Long)``````

Parameters

source
IEnumerable<Nullable<Int64>>

A sequence of nullable Int64 values to calculate the sum of.

Returns

The sum of the values in the sequence.

Exceptions

`source` is `null`.

The sum is larger than Int64.MaxValue.

Remarks

Items in `source` that are `null` are excluded from the computation of the sum. This method returns zero if `source` contains no elements or all elements are `null`.

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

Sum(IEnumerable<Nullable<Double>>)

Computes the sum of a sequence of nullable Double values.

``````public:
[System::Runtime::CompilerServices::Extension]
static Nullable<double> Sum(System::Collections::Generic::IEnumerable<Nullable<double>> ^ source);``````
``public static double? Sum (this System.Collections.Generic.IEnumerable<double?> source);``
``static member Sum : seq<Nullable<double>> -> Nullable<double>``
``````<Extension()>
Public Function Sum (source As IEnumerable(Of Nullable(Of Double))) As Nullable(Of Double)``````

Parameters

source
IEnumerable<Nullable<Double>>

A sequence of nullable Double values to calculate the sum of.

Returns

The sum of the values in the sequence.

Exceptions

`source` is `null`.

The sum is larger than Double.MaxValue.

Remarks

Items in `source` that are `null` are excluded from the computation of the sum. This method returns zero if `source` contains no elements or all elements are `null`.

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

Sum(IEnumerable<Int32>)

Computes the sum of a sequence of Int32 values.

``````public:
[System::Runtime::CompilerServices::Extension]
static int Sum(System::Collections::Generic::IEnumerable<int> ^ source);``````
``public static int Sum (this System.Collections.Generic.IEnumerable<int> source);``
``static member Sum : seq<int> -> int``
``````<Extension()>
Public Function Sum (source As IEnumerable(Of Integer)) As Integer``````

Parameters

source
IEnumerable<Int32>

A sequence of Int32 values to calculate the sum of.

Returns

The sum of the values in the sequence.

Exceptions

`source` is `null`.

The sum is larger than Int32.MaxValue.

Remarks

This method returns zero if `source` contains no elements.

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

Sum(IEnumerable<Int64>)

Computes the sum of a sequence of Int64 values.

``````public:
[System::Runtime::CompilerServices::Extension]
static long Sum(System::Collections::Generic::IEnumerable<long> ^ source);``````
``public static long Sum (this System.Collections.Generic.IEnumerable<long> source);``
``static member Sum : seq<int64> -> int64``
``````<Extension()>
Public Function Sum (source As IEnumerable(Of Long)) As Long``````

Parameters

source
IEnumerable<Int64>

A sequence of Int64 values to calculate the sum of.

Returns

The sum of the values in the sequence.

Exceptions

`source` is `null`.

The sum is larger than Int64.MaxValue.

Remarks

This method returns zero if `source` contains no elements.

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

Sum(IEnumerable<Double>)

Computes the sum of a sequence of Double values.

``````public:
[System::Runtime::CompilerServices::Extension]
static double Sum(System::Collections::Generic::IEnumerable<double> ^ source);``````
``public static double Sum (this System.Collections.Generic.IEnumerable<double> source);``
``static member Sum : seq<double> -> double``
``````<Extension()>
Public Function Sum (source As IEnumerable(Of Double)) As Double``````

Parameters

source
IEnumerable<Double>

A sequence of Double values to calculate the sum of.

Returns

The sum of the values in the sequence.

Exceptions

`source` is `null`.

The sum is larger than Double.MaxValue.

Remarks

This method returns zero if `source` contains no elements.

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

Sum(IEnumerable<Decimal>)

Computes the sum of a sequence of Decimal values.

``````public:
[System::Runtime::CompilerServices::Extension]
static System::Decimal Sum(System::Collections::Generic::IEnumerable<System::Decimal> ^ source);``````
``public static decimal Sum (this System.Collections.Generic.IEnumerable<decimal> source);``
``static member Sum : seq<decimal> -> decimal``
``````<Extension()>
Public Function Sum (source As IEnumerable(Of Decimal)) As Decimal``````

Parameters

source
IEnumerable<Decimal>

A sequence of Decimal values to calculate the sum of.

Returns

The sum of the values in the sequence.

Exceptions

`source` is `null`.

The sum is larger than Decimal.MaxValue.

Remarks

The Sum(IEnumerable<Decimal>) method returns zero if `source` contains no elements.

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

Sum(IEnumerable<Nullable<Decimal>>)

Computes the sum of a sequence of nullable Decimal values.

``````public:
[System::Runtime::CompilerServices::Extension]
static Nullable<System::Decimal> Sum(System::Collections::Generic::IEnumerable<Nullable<System::Decimal>> ^ source);``````
``public static decimal? Sum (this System.Collections.Generic.IEnumerable<decimal?> source);``
``static member Sum : seq<Nullable<decimal>> -> Nullable<decimal>``
``````<Extension()>
Public Function Sum (source As IEnumerable(Of Nullable(Of Decimal))) As Nullable(Of Decimal)``````

Parameters

source
IEnumerable<Nullable<Decimal>>

A sequence of nullable Decimal values to calculate the sum of.

Returns

The sum of the values in the sequence.

Exceptions

`source` is `null`.

The sum is larger than Decimal.MaxValue.

Remarks

Items in `source` that are `null` are excluded from the computation of the sum. This method returns zero if `source` contains no elements or all elements are `null`.

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

Sum<TSource>(IEnumerable<TSource>, Func<TSource,Single>)

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

``````public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static float Sum(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, float> ^ selector);``````
``public static float Sum<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,float> selector);``
``static member Sum : seq<'Source> * Func<'Source, single> -> single``
``````<Extension()>
Public Function Sum(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Single)) As Single``````

Type Parameters

TSource

The type of the elements of `source`.

Parameters

source
IEnumerable<TSource>

A sequence of values that are used to calculate a sum.

selector
Func<TSource,Single>

A transform function to apply to each element.

Returns

The sum of the projected values.

Exceptions

`source` or `selector` is `null`.

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 the method that's different from the specific overload that this article describes. To extend the example to the overload that this article describes, change the body of the `selector` function.

``````class Package
{
public string Company { get; set; }
public double Weight { get; set; }
}

public static void SumEx1()
{
List<Package> packages =
new List<Package>
{ new Package { Company = "Coho Vineyard", Weight = 25.2 },
new Package { Company = "Lucerne Publishing", Weight = 18.7 },
new Package { Company = "Wingtip Toys", Weight = 6.0 },
new Package { Company = "Adventure Works", Weight = 33.8 } };

double totalWeight = packages.Sum(pkg => pkg.Weight);

Console.WriteLine("The total weight of the packages is: {0}", totalWeight);
}

/*
This code produces the following output:

The total weight of the packages is: 83.7
*/
``````
``````Structure Package
Public Company As String
Public Weight As Double
End Structure

Sub SumEx1()
' Create a list of Package values.
Dim packages As New List(Of Package)(New Package() _
{New Package With {.Company = "Coho Vineyard", .Weight = 25.2},
New Package With {.Company = "Lucerne Publishing", .Weight = 18.7},
New Package With {.Company = "Wingtip Toys", .Weight = 6.0},
New Package With {.Company = "Adventure Works", .Weight = 33.8}})

' Sum the values from each item's Weight property.
Dim totalWeight As Double = packages.Sum(Function(pkg) _
pkg.Weight)

' Display the result.
Console.WriteLine(\$"The total weight of the packages is: {totalWeight}")
End Sub

' This code produces the following output:
'
' The total weight of the packages is: 83.7
``````

Remarks

The Sum<TSource>(IEnumerable<TSource>, Func<TSource,Single>) 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 Single.

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

Sum<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int64>>)

Computes the sum of the sequence of nullable Int64 values that are obtained by invoking a transform function on each element of the input sequence.

``````public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static Nullable<long> Sum(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, Nullable<long>> ^ selector);``````
``public static long? Sum<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,long?> selector);``
``static member Sum : seq<'Source> * Func<'Source, Nullable<int64>> -> Nullable<int64>``
``````<Extension()>
Public Function Sum(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Nullable(Of Long))) As Nullable(Of Long)``````

Type Parameters

TSource

The type of the elements of `source`.

Parameters

source
IEnumerable<TSource>

A sequence of values that are used to calculate a sum.

selector
Func<TSource,Nullable<Int64>>

A transform function to apply to each element.

Returns

The sum of the projected values.

Exceptions

`source` or `selector` is `null`.

The sum is larger than Int64.MaxValue.

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 the method that's different from the specific overload that this article describes. To extend the example to the overload that this article describes, change the body of the `selector` function.

``````class Package
{
public string Company { get; set; }
public double Weight { get; set; }
}

public static void SumEx1()
{
List<Package> packages =
new List<Package>
{ new Package { Company = "Coho Vineyard", Weight = 25.2 },
new Package { Company = "Lucerne Publishing", Weight = 18.7 },
new Package { Company = "Wingtip Toys", Weight = 6.0 },
new Package { Company = "Adventure Works", Weight = 33.8 } };

double totalWeight = packages.Sum(pkg => pkg.Weight);

Console.WriteLine("The total weight of the packages is: {0}", totalWeight);
}

/*
This code produces the following output:

The total weight of the packages is: 83.7
*/
``````
``````Structure Package
Public Company As String
Public Weight As Double
End Structure

Sub SumEx1()
' Create a list of Package values.
Dim packages As New List(Of Package)(New Package() _
{New Package With {.Company = "Coho Vineyard", .Weight = 25.2},
New Package With {.Company = "Lucerne Publishing", .Weight = 18.7},
New Package With {.Company = "Wingtip Toys", .Weight = 6.0},
New Package With {.Company = "Adventure Works", .Weight = 33.8}})

' Sum the values from each item's Weight property.
Dim totalWeight As Double = packages.Sum(Function(pkg) _
pkg.Weight)

' Display the result.
Console.WriteLine(\$"The total weight of the packages is: {totalWeight}")
End Sub

' This code produces the following output:
'
' The total weight of the packages is: 83.7
``````

Remarks

Items in `source` that are `null` are excluded from the computation of the sum. This method returns zero if `source` contains no elements or all elements are `null`.

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<Int64>` in C# or `Nullable(Of Int64)` in Visual Basic

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

Sum<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int32>>)

Computes the sum of the sequence of nullable Int32 values that are obtained by invoking a transform function on each element of the input sequence.

``````public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static Nullable<int> Sum(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, Nullable<int>> ^ selector);``````
``public static int? Sum<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,int?> selector);``
``static member Sum : seq<'Source> * Func<'Source, Nullable<int>> -> Nullable<int>``
``````<Extension()>
Public Function Sum(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Nullable(Of Integer))) As Nullable(Of Integer)``````

Type Parameters

TSource

The type of the elements of `source`.

Parameters

source
IEnumerable<TSource>

A sequence of values that are used to calculate a sum.

selector
Func<TSource,Nullable<Int32>>

A transform function to apply to each element.

Returns

The sum of the projected values.

Exceptions

`source` or `selector` is `null`.

The sum is larger than Int32.MaxValue.

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 the method that's different from the specific overload that this article describes. To extend the example to the overload that this article describes, change the body of the `selector` function.

``````class Package
{
public string Company { get; set; }
public double Weight { get; set; }
}

public static void SumEx1()
{
List<Package> packages =
new List<Package>
{ new Package { Company = "Coho Vineyard", Weight = 25.2 },
new Package { Company = "Lucerne Publishing", Weight = 18.7 },
new Package { Company = "Wingtip Toys", Weight = 6.0 },
new Package { Company = "Adventure Works", Weight = 33.8 } };

double totalWeight = packages.Sum(pkg => pkg.Weight);

Console.WriteLine("The total weight of the packages is: {0}", totalWeight);
}

/*
This code produces the following output:

The total weight of the packages is: 83.7
*/
``````
``````Structure Package
Public Company As String
Public Weight As Double
End Structure

Sub SumEx1()
' Create a list of Package values.
Dim packages As New List(Of Package)(New Package() _
{New Package With {.Company = "Coho Vineyard", .Weight = 25.2},
New Package With {.Company = "Lucerne Publishing", .Weight = 18.7},
New Package With {.Company = "Wingtip Toys", .Weight = 6.0},
New Package With {.Company = "Adventure Works", .Weight = 33.8}})

' Sum the values from each item's Weight property.
Dim totalWeight As Double = packages.Sum(Function(pkg) _
pkg.Weight)

' Display the result.
Console.WriteLine(\$"The total weight of the packages is: {totalWeight}")
End Sub

' This code produces the following output:
'
' The total weight of the packages is: 83.7
``````

Remarks

Items in `source` that are `null` are excluded from the computation of the sum. This method returns zero if `source` contains no elements or all elements are `null`.

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<Int32>` in C# or `Nullable(Of Int32)` in Visual Basic.

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

Sum<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Double>>)

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

``````public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static Nullable<double> Sum(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, Nullable<double>> ^ selector);``````
``public static double? Sum<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,double?> selector);``
``static member Sum : seq<'Source> * Func<'Source, Nullable<double>> -> Nullable<double>``
``````<Extension()>
Public Function Sum(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Nullable(Of Double))) As Nullable(Of Double)``````

Type Parameters

TSource

The type of the elements of `source`.

Parameters

source
IEnumerable<TSource>

A sequence of values that are used to calculate a sum.

selector
Func<TSource,Nullable<Double>>

A transform function to apply to each element.

Returns

The sum of the projected values.

Exceptions

`source` or `selector` is `null`.

The sum is larger than Double.MaxValue.

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 the method that's different from the specific overload that this article describes. To extend the example to the overload that this article describes, change the body of the `selector` function.

``````class Package
{
public string Company { get; set; }
public double Weight { get; set; }
}

public static void SumEx1()
{
List<Package> packages =
new List<Package>
{ new Package { Company = "Coho Vineyard", Weight = 25.2 },
new Package { Company = "Lucerne Publishing", Weight = 18.7 },
new Package { Company = "Wingtip Toys", Weight = 6.0 },
new Package { Company = "Adventure Works", Weight = 33.8 } };

double totalWeight = packages.Sum(pkg => pkg.Weight);

Console.WriteLine("The total weight of the packages is: {0}", totalWeight);
}

/*
This code produces the following output:

The total weight of the packages is: 83.7
*/
``````
``````Structure Package
Public Company As String
Public Weight As Double
End Structure

Sub SumEx1()
' Create a list of Package values.
Dim packages As New List(Of Package)(New Package() _
{New Package With {.Company = "Coho Vineyard", .Weight = 25.2},
New Package With {.Company = "Lucerne Publishing", .Weight = 18.7},
New Package With {.Company = "Wingtip Toys", .Weight = 6.0},
New Package With {.Company = "Adventure Works", .Weight = 33.8}})

' Sum the values from each item's Weight property.
Dim totalWeight As Double = packages.Sum(Function(pkg) _
pkg.Weight)

' Display the result.
Console.WriteLine(\$"The total weight of the packages is: {totalWeight}")
End Sub

' This code produces the following output:
'
' The total weight of the packages is: 83.7
``````

Remarks

Items in `source` that are `null` are excluded from the computation of the sum. This method returns zero if `source` contains no elements or all elements are `null`.

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<Double>` in C# or `Nullable(Of Double)` in Visual Basic.

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

Sum<TSource>(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.

``````public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static Nullable<float> Sum(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, Nullable<float>> ^ selector);``````
``public static float? Sum<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,float?> selector);``
``static member Sum : seq<'Source> * Func<'Source, Nullable<single>> -> Nullable<single>``
``````<Extension()>
Public Function Sum(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Nullable(Of Single))) As Nullable(Of Single)``````

Type Parameters

TSource

The type of the elements of `source`.

Parameters

source
IEnumerable<TSource>

A sequence of values that are used to calculate a sum.

selector
Func<TSource,Nullable<Single>>

A transform function to apply to each element.

Returns

The sum of the projected values.

Exceptions

`source` or `selector` is `null`.

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 the method that's different from the specific overload that this article describes. To extend the example to the overload that this article describes, change the body of the `selector` function.

``````class Package
{
public string Company { get; set; }
public double Weight { get; set; }
}

public static void SumEx1()
{
List<Package> packages =
new List<Package>
{ new Package { Company = "Coho Vineyard", Weight = 25.2 },
new Package { Company = "Lucerne Publishing", Weight = 18.7 },
new Package { Company = "Wingtip Toys", Weight = 6.0 },
new Package { Company = "Adventure Works", Weight = 33.8 } };

double totalWeight = packages.Sum(pkg => pkg.Weight);

Console.WriteLine("The total weight of the packages is: {0}", totalWeight);
}

/*
This code produces the following output:

The total weight of the packages is: 83.7
*/
``````
``````Structure Package
Public Company As String
Public Weight As Double
End Structure

Sub SumEx1()
' Create a list of Package values.
Dim packages As New List(Of Package)(New Package() _
{New Package With {.Company = "Coho Vineyard", .Weight = 25.2},
New Package With {.Company = "Lucerne Publishing", .Weight = 18.7},
New Package With {.Company = "Wingtip Toys", .Weight = 6.0},
New Package With {.Company = "Adventure Works", .Weight = 33.8}})

' Sum the values from each item's Weight property.
Dim totalWeight As Double = packages.Sum(Function(pkg) _
pkg.Weight)

' Display the result.
Console.WriteLine(\$"The total weight of the packages is: {totalWeight}")
End Sub

' This code produces the following output:
'
' The total weight of the packages is: 83.7
``````

Remarks

Items in `source` that are `null` are excluded from the computation of the sum. This method returns zero if `source` contains no elements or all elements are `null`.

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.

Sum<TSource>(IEnumerable<TSource>, Func<TSource,Int64>)

Computes the sum of the sequence of Int64 values that are obtained by invoking a transform function on each element of the input sequence.

``````public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static long Sum(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, long> ^ selector);``````
``public static long Sum<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,long> selector);``
``static member Sum : seq<'Source> * Func<'Source, int64> -> int64``
``````<Extension()>
Public Function Sum(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Long)) As Long``````

Type Parameters

TSource

The type of the elements of `source`.

Parameters

source
IEnumerable<TSource>

A sequence of values that are used to calculate a sum.

selector
Func<TSource,Int64>

A transform function to apply to each element.

Returns

The sum of the projected values.

Exceptions

`source` or `selector` is `null`.

The sum is larger than Int64.MaxValue.

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 the method that's different from the specific overload that this article describes. To extend the example to the overload that this article describes, change the body of the `selector` function.

``````class Package
{
public string Company { get; set; }
public double Weight { get; set; }
}

public static void SumEx1()
{
List<Package> packages =
new List<Package>
{ new Package { Company = "Coho Vineyard", Weight = 25.2 },
new Package { Company = "Lucerne Publishing", Weight = 18.7 },
new Package { Company = "Wingtip Toys", Weight = 6.0 },
new Package { Company = "Adventure Works", Weight = 33.8 } };

double totalWeight = packages.Sum(pkg => pkg.Weight);

Console.WriteLine("The total weight of the packages is: {0}", totalWeight);
}

/*
This code produces the following output:

The total weight of the packages is: 83.7
*/
``````
``````Structure Package
Public Company As String
Public Weight As Double
End Structure

Sub SumEx1()
' Create a list of Package values.
Dim packages As New List(Of Package)(New Package() _
{New Package With {.Company = "Coho Vineyard", .Weight = 25.2},
New Package With {.Company = "Lucerne Publishing", .Weight = 18.7},
New Package With {.Company = "Wingtip Toys", .Weight = 6.0},
New Package With {.Company = "Adventure Works", .Weight = 33.8}})

' Sum the values from each item's Weight property.
Dim totalWeight As Double = packages.Sum(Function(pkg) _
pkg.Weight)

' Display the result.
Console.WriteLine(\$"The total weight of the packages is: {totalWeight}")
End Sub

' This code produces the following output:
'
' The total weight of the packages is: 83.7
``````

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 Int64.

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

Sum<TSource>(IEnumerable<TSource>, Func<TSource,Int32>)

Computes the sum of the sequence of Int32 values that are obtained by invoking a transform function on each element of the input sequence.

``````public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static int Sum(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, int> ^ selector);``````
``public static int Sum<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,int> selector);``
``static member Sum : seq<'Source> * Func<'Source, int> -> int``
``````<Extension()>
Public Function Sum(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Integer)) As Integer``````

Type Parameters

TSource

The type of the elements of `source`.

Parameters

source
IEnumerable<TSource>

A sequence of values that are used to calculate a sum.

selector
Func<TSource,Int32>

A transform function to apply to each element.

Returns

The sum of the projected values.

Exceptions

`source` or `selector` is `null`.

The sum is larger than Int32.MaxValue.

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 the method that's different from the specific overload that this article describes. To extend the example to the overload that this article describes, change the body of the `selector` function.

``````class Package
{
public string Company { get; set; }
public double Weight { get; set; }
}

public static void SumEx1()
{
List<Package> packages =
new List<Package>
{ new Package { Company = "Coho Vineyard", Weight = 25.2 },
new Package { Company = "Lucerne Publishing", Weight = 18.7 },
new Package { Company = "Wingtip Toys", Weight = 6.0 },
new Package { Company = "Adventure Works", Weight = 33.8 } };

double totalWeight = packages.Sum(pkg => pkg.Weight);

Console.WriteLine("The total weight of the packages is: {0}", totalWeight);
}

/*
This code produces the following output:

The total weight of the packages is: 83.7
*/
``````
``````Structure Package
Public Company As String
Public Weight As Double
End Structure

Sub SumEx1()
' Create a list of Package values.
Dim packages As New List(Of Package)(New Package() _
{New Package With {.Company = "Coho Vineyard", .Weight = 25.2},
New Package With {.Company = "Lucerne Publishing", .Weight = 18.7},
New Package With {.Company = "Wingtip Toys", .Weight = 6.0},
New Package With {.Company = "Adventure Works", .Weight = 33.8}})

' Sum the values from each item's Weight property.
Dim totalWeight As Double = packages.Sum(Function(pkg) _
pkg.Weight)

' Display the result.
Console.WriteLine(\$"The total weight of the packages is: {totalWeight}")
End Sub

' This code produces the following output:
'
' The total weight of the packages is: 83.7
``````

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 Int32.

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

Sum<TSource>(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.

``````public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static double Sum(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, double> ^ selector);``````
``public static double Sum<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,double> selector);``
``static member Sum : seq<'Source> * Func<'Source, double> -> double``
``````<Extension()>
Public Function Sum(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Double)) As Double``````

Type Parameters

TSource

The type of the elements of `source`.

Parameters

source
IEnumerable<TSource>

A sequence of values that are used to calculate a sum.

selector
Func<TSource,Double>

A transform function to apply to each element.

Returns

The sum of the projected values.

Exceptions

`source` or `selector` is `null`.

The sum is larger than Double.MaxValue.

Examples

The following code example demonstrates how to use Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) to sum the projected values of a sequence.

``````class Package
{
public string Company { get; set; }
public double Weight { get; set; }
}

public static void SumEx1()
{
List<Package> packages =
new List<Package>
{ new Package { Company = "Coho Vineyard", Weight = 25.2 },
new Package { Company = "Lucerne Publishing", Weight = 18.7 },
new Package { Company = "Wingtip Toys", Weight = 6.0 },
new Package { Company = "Adventure Works", Weight = 33.8 } };

double totalWeight = packages.Sum(pkg => pkg.Weight);

Console.WriteLine("The total weight of the packages is: {0}", totalWeight);
}

/*
This code produces the following output:

The total weight of the packages is: 83.7
*/
``````
``````Structure Package
Public Company As String
Public Weight As Double
End Structure

Sub SumEx1()
' Create a list of Package values.
Dim packages As New List(Of Package)(New Package() _
{New Package With {.Company = "Coho Vineyard", .Weight = 25.2},
New Package With {.Company = "Lucerne Publishing", .Weight = 18.7},
New Package With {.Company = "Wingtip Toys", .Weight = 6.0},
New Package With {.Company = "Adventure Works", .Weight = 33.8}})

' Sum the values from each item's Weight property.
Dim totalWeight As Double = packages.Sum(Function(pkg) _
pkg.Weight)

' Display the result.
Console.WriteLine(\$"The total weight of the packages is: {totalWeight}")
End Sub

' This code produces the following output:
'
' The total weight of the packages is: 83.7
``````

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 Double.

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

Sum<TSource>(IEnumerable<TSource>, Func<TSource,Decimal>)

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

``````public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static System::Decimal Sum(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, System::Decimal> ^ selector);``````
``public static decimal Sum<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,decimal> selector);``
``static member Sum : seq<'Source> * Func<'Source, decimal> -> decimal``
``````<Extension()>
Public Function Sum(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Decimal)) As Decimal``````

Type Parameters

TSource

The type of the elements of `source`.

Parameters

source
IEnumerable<TSource>

A sequence of values that are used to calculate a sum.

selector
Func<TSource,Decimal>

A transform function to apply to each element.

Returns

The sum of the projected values.

Exceptions

`source` or `selector` is `null`.

The sum is larger than Decimal.MaxValue.

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 the method that's different from the specific overload that this article describes. To extend the example to the overload that this article describes, change the body of the `selector` function.

``````class Package
{
public string Company { get; set; }
public double Weight { get; set; }
}

public static void SumEx1()
{
List<Package> packages =
new List<Package>
{ new Package { Company = "Coho Vineyard", Weight = 25.2 },
new Package { Company = "Lucerne Publishing", Weight = 18.7 },
new Package { Company = "Wingtip Toys", Weight = 6.0 },
new Package { Company = "Adventure Works", Weight = 33.8 } };

double totalWeight = packages.Sum(pkg => pkg.Weight);

Console.WriteLine("The total weight of the packages is: {0}", totalWeight);
}

/*
This code produces the following output:

The total weight of the packages is: 83.7
*/
``````
``````Structure Package
Public Company As String
Public Weight As Double
End Structure

Sub SumEx1()
' Create a list of Package values.
Dim packages As New List(Of Package)(New Package() _
{New Package With {.Company = "Coho Vineyard", .Weight = 25.2},
New Package With {.Company = "Lucerne Publishing", .Weight = 18.7},
New Package With {.Company = "Wingtip Toys", .Weight = 6.0},
New Package With {.Company = "Adventure Works", .Weight = 33.8}})

' Sum the values from each item's Weight property.
Dim totalWeight As Double = packages.Sum(Function(pkg) _
pkg.Weight)

' Display the result.
Console.WriteLine(\$"The total weight of the packages is: {totalWeight}")
End Sub

' This code produces the following output:
'
' The total weight of the packages is: 83.7
``````

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.

Sum<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Decimal>>)

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

``````public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static Nullable<System::Decimal> Sum(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, Nullable<System::Decimal>> ^ selector);``````
``public static decimal? Sum<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,decimal?> selector);``
``static member Sum : seq<'Source> * Func<'Source, Nullable<decimal>> -> Nullable<decimal>``
``````<Extension()>
Public Function Sum(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Nullable(Of Decimal))) As Nullable(Of Decimal)``````

Type Parameters

TSource

The type of the elements of `source`.

Parameters

source
IEnumerable<TSource>

A sequence of values that are used to calculate a sum.

selector
Func<TSource,Nullable<Decimal>>

A transform function to apply to each element.

Returns

The sum of the projected values.

Exceptions

`source` or `selector` is `null`.

The sum is larger than Decimal.MaxValue.

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 the method that's different from the specific overload that this article describes. To extend the example to the overload that this article describes, change the body of the `selector` function.

``````class Package
{
public string Company { get; set; }
public double Weight { get; set; }
}

public static void SumEx1()
{
List<Package> packages =
new List<Package>
{ new Package { Company = "Coho Vineyard", Weight = 25.2 },
new Package { Company = "Lucerne Publishing", Weight = 18.7 },
new Package { Company = "Wingtip Toys", Weight = 6.0 },
new Package { Company = "Adventure Works", Weight = 33.8 } };

double totalWeight = packages.Sum(pkg => pkg.Weight);

Console.WriteLine("The total weight of the packages is: {0}", totalWeight);
}

/*
This code produces the following output:

The total weight of the packages is: 83.7
*/
``````
``````Structure Package
Public Company As String
Public Weight As Double
End Structure

Sub SumEx1()
' Create a list of Package values.
Dim packages As New List(Of Package)(New Package() _
{New Package With {.Company = "Coho Vineyard", .Weight = 25.2},
New Package With {.Company = "Lucerne Publishing", .Weight = 18.7},
New Package With {.Company = "Wingtip Toys", .Weight = 6.0},
New Package With {.Company = "Adventure Works", .Weight = 33.8}})

' Sum the values from each item's Weight property.
Dim totalWeight As Double = packages.Sum(Function(pkg) _
pkg.Weight)

' Display the result.
Console.WriteLine(\$"The total weight of the packages is: {totalWeight}")
End Sub

' This code produces the following output:
'
' The total weight of the packages is: 83.7
``````

Remarks

Items in `source` that are `null` are excluded from the computation of the sum. This method returns zero if `source` contains no elements or all elements are `null`.

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<Decimal>` in C# or `Nullable(Of Decimal)` in Visual Basic.

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