Enumerable.Sum Method

Definition

計算數值序列的總和。Computes the sum of a sequence of numeric values.

Overloads

Sum(IEnumerable<Nullable<Int32>>)

計算可為 Null 之 Int32 值序列的總和。Computes the sum of a sequence of nullable Int32 values.

Sum(IEnumerable<Nullable<Single>>)

計算可為 Null 之 Single 值序列的總和。Computes the sum of a sequence of nullable Single values.

Sum(IEnumerable<Nullable<Int64>>)

計算可為 Null 之 Int64 值序列的總和。Computes the sum of a sequence of nullable Int64 values.

Sum(IEnumerable<Single>)

計算 Single 值序列的總和。Computes the sum of a sequence of Single values.

Sum(IEnumerable<Nullable<Double>>)

計算可為 Null 之 Double 值序列的總和。Computes the sum of a sequence of nullable Double values.

Sum(IEnumerable<Int32>)

計算 Int32 值序列的總和。Computes the sum of a sequence of Int32 values.

Sum(IEnumerable<Int64>)

計算 Int64 值序列的總和。Computes the sum of a sequence of Int64 values.

Sum(IEnumerable<Double>)

計算 Double 值序列的總和。Computes the sum of a sequence of Double values.

Sum(IEnumerable<Decimal>)

計算 Decimal 值序列的總和。Computes the sum of a sequence of Decimal values.

Sum(IEnumerable<Nullable<Decimal>>)

計算可為 Null 之 Decimal 值序列的總和。Computes the sum of a sequence of nullable Decimal values.

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

計算在輸入序列中各項目上叫用轉換函式後所取得之 Single 值序列的總和。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<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Single>>)

計算在輸入序列中各項目上叫用轉換函式後所取得可為 Null 之 Single 值的總和。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<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int64>>)

計算在輸入序列中各項目上叫用轉換函式後所取得可為 Null 之 Int64 值的總和。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<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int32>>)

計算在輸入序列中各項目上叫用轉換函式後所取得可為 Null 之 Int32 值的總和。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<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Double>>)

計算在輸入序列中各項目上叫用轉換函式後所取得可為 Null 之 Double 值的總和。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<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Decimal>>)

計算在輸入序列中各項目上叫用轉換函式後所取得可為 Null 之 Decimal 值的總和。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<TSource>(IEnumerable<TSource>, Func<TSource,Int64>)

計算在輸入序列中各項目上叫用轉換函式後所取得之 Int64 值序列的總和。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<TSource>(IEnumerable<TSource>, Func<TSource,Int32>)

計算在輸入序列中各項目上叫用轉換函式後所取得之 Int32 值序列的總和。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<TSource>(IEnumerable<TSource>, Func<TSource,Double>)

計算在輸入序列中各項目上叫用轉換函式後所取得之 Double 值序列的總和。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<TSource>(IEnumerable<TSource>, Func<TSource,Decimal>)

計算在輸入序列中各項目上叫用轉換函式後所取得之 Decimal 值序列的總和。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<Nullable<Int32>>)

計算可為 Null 之 Int32 值序列的總和。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<Nullable<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>>

要計算總和之可為 Null 的 Int32 值序列。A sequence of nullable Int32 values to calculate the sum of.

Returns

Nullable<Int32>

序列中值的總合。The sum of the values in the sequence.

Exceptions

sourcenullsource is null.

總和大於 MaxValueThe sum is larger than MaxValue.

Examples

下列程式碼範例示範如何使用 Sum(IEnumerable<Nullable<Single>>) 來加總序列的值。The following code example demonstrates how to use Sum(IEnumerable<Nullable<Single>>) to sum the values of a sequence.

Note

這個程式碼範例會使用此多載方法的多載,這個多載不是本主題描述的特定多載。This code example uses an overload of this overloaded method that is different from the specific overload that this topic describes. 若要擴充範例以符合本主題內容,請以具有適當數值類型的項目取代來源序列的項目。To extend the example to this topic, substitute the elements of the source sequence with elements of the appropriate numerical type.

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

如果 source 未包含任何元素,這個方法會傳回零。This method returns zero if source contains no elements.

結果不包含 null的值。The result does not include values that are null.

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

Sum(IEnumerable<Nullable<Single>>)

計算可為 Null 之 Single 值序列的總和。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<Nullable<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>>

要計算總和之可為 Null 的 Single 值序列。A sequence of nullable Single values to calculate the sum of.

Returns

Nullable<Single>

序列中值的總合。The sum of the values in the sequence.

Exceptions

sourcenullsource is null.

Examples

下列程式碼範例示範如何使用 Sum(IEnumerable<Nullable<Single>>) 來加總序列的值。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

如果 source 未包含任何元素,這個方法會傳回零。This method returns zero if source contains no elements.

結果不包含 null的值。The result does not include values that are null.

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

Sum(IEnumerable<Nullable<Int64>>)

計算可為 Null 之 Int64 值序列的總和。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<Nullable<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>>

要計算總和之可為 Null 的 Int64 值序列。A sequence of nullable Int64 values to calculate the sum of.

Returns

Nullable<Int64>

序列中值的總合。The sum of the values in the sequence.

Exceptions

sourcenullsource is null.

總和大於 MaxValueThe sum is larger than MaxValue.

Examples

下列程式碼範例示範如何使用 Sum(IEnumerable<Nullable<Single>>) 來加總序列的值。The following code example demonstrates how to use Sum(IEnumerable<Nullable<Single>>) to sum the values of a sequence.

Note

這個程式碼範例會使用此多載方法的多載,這個多載不是本主題描述的特定多載。This code example uses an overload of this overloaded method that is different from the specific overload that this topic describes. 若要擴充範例以符合本主題內容,請以具有適當數值類型的項目取代來源序列的項目。To extend the example to this topic, substitute the elements of the source sequence with elements of the appropriate numerical type.

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

如果 source 未包含任何元素,這個方法會傳回零。This method returns zero if source contains no elements.

結果不包含 null的值。The result does not include values that are null.

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

Sum(IEnumerable<Single>)

計算 Single 值序列的總和。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>

要計算總和的 Single 值序列。A sequence of Single values to calculate the sum of.

Returns

Single

序列中值的總合。The sum of the values in the sequence.

Exceptions

sourcenullsource is null.

Examples

下列程式碼範例示範如何使用 Sum(IEnumerable<Single>) 來加總序列的值。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

如果 source 未包含任何元素,這個方法會傳回零。This method returns zero if source contains no elements.

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

Sum(IEnumerable<Nullable<Double>>)

計算可為 Null 之 Double 值序列的總和。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<Nullable<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>>

要計算總和之可為 Null 的 Double 值序列。A sequence of nullable Double values to calculate the sum of.

Returns

Nullable<Double>

序列中值的總合。The sum of the values in the sequence.

Exceptions

sourcenullsource is null.

Examples

下列程式碼範例示範如何使用 Sum(IEnumerable<Nullable<Single>>) 來加總序列的值。The following code example demonstrates how to use Sum(IEnumerable<Nullable<Single>>) to sum the values of a sequence.

Note

這個程式碼範例會使用此多載方法的多載,這個多載不是本主題描述的特定多載。This code example uses an overload of this overloaded method that is different from the specific overload that this topic describes. 若要擴充範例以符合本主題內容,請以具有適當數值類型的項目取代來源序列的項目。To extend the example to this topic, substitute the elements of the source sequence with elements of the appropriate numerical type.

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

如果 source 未包含任何元素,這個方法會傳回零。This method returns zero if source contains no elements.

結果不包含 null的值。The result does not include values that are null.

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

Sum(IEnumerable<Int32>)

計算 Int32 值序列的總和。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>

要計算總和的 Int32 值序列。A sequence of Int32 values to calculate the sum of.

Returns

Int32

序列中值的總合。The sum of the values in the sequence.

Exceptions

sourcenullsource is null.

總和大於 MaxValueThe sum is larger than MaxValue.

Examples

下列程式碼範例示範如何使用 Sum(IEnumerable<Single>) 來加總序列的值。The following code example demonstrates how to use Sum(IEnumerable<Single>) to sum the values of a sequence.

Note

這個程式碼範例會使用此多載方法的多載,這個多載不是本主題描述的特定多載。This code example uses an overload of this overloaded method that is different from the specific overload that this topic describes. 若要擴充範例以符合本主題內容,請以具有適當數值類型的項目取代來源序列的項目。To extend the example to this topic, substitute the elements of the source sequence with elements of the appropriate numerical type.

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

如果 source 未包含任何元素,這個方法會傳回零。This method returns zero if source contains no elements.

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

Sum(IEnumerable<Int64>)

計算 Int64 值序列的總和。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>

要計算總和的 Int64 值序列。A sequence of Int64 values to calculate the sum of.

Returns

Int64

序列中值的總合。The sum of the values in the sequence.

Exceptions

sourcenullsource is null.

總和大於 MaxValueThe sum is larger than MaxValue.

Examples

下列程式碼範例示範如何使用 Sum(IEnumerable<Single>) 來加總序列的值。The following code example demonstrates how to use Sum(IEnumerable<Single>) to sum the values of a sequence.

Note

這個程式碼範例會使用此多載方法的多載,這個多載不是本主題描述的特定多載。This code example uses an overload of this overloaded method that is different from the specific overload that this topic describes. 若要擴充範例以符合本主題內容,請以具有適當數值類型的項目取代來源序列的項目。To extend the example to this topic, substitute the elements of the source sequence with elements of the appropriate numerical type.

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

如果 source 未包含任何元素,這個方法會傳回零。This method returns zero if source contains no elements.

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

Sum(IEnumerable<Double>)

計算 Double 值序列的總和。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>

要計算總和的 Double 值序列。A sequence of Double values to calculate the sum of.

Returns

Double

序列中值的總合。The sum of the values in the sequence.

Exceptions

sourcenullsource is null.

Examples

下列程式碼範例示範如何使用 Sum(IEnumerable<Single>) 來加總序列的值。The following code example demonstrates how to use Sum(IEnumerable<Single>) to sum the values of a sequence.

Note

這個程式碼範例會使用此多載方法的多載,這個多載不是本主題描述的特定多載。This code example uses an overload of this overloaded method that is different from the specific overload that this topic describes. 若要擴充範例以符合本主題內容,請以具有適當數值類型的項目取代來源序列的項目。To extend the example to this topic, substitute the elements of the source sequence with elements of the appropriate numerical type.

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

如果 source 未包含任何元素,這個方法會傳回零。This method returns zero if source contains no elements.

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

Sum(IEnumerable<Decimal>)

計算 Decimal 值序列的總和。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>

要計算總和的 Decimal 值序列。A sequence of Decimal values to calculate the sum of.

Returns

Decimal

序列中值的總合。The sum of the values in the sequence.

Exceptions

sourcenullsource is null.

總和大於 MaxValueThe sum is larger than MaxValue.

Examples

下列程式碼範例示範如何使用 Sum(IEnumerable<Single>) 來加總序列的值。The following code example demonstrates how to use Sum(IEnumerable<Single>) to sum the values of a sequence.

Note

這個程式碼範例會使用此多載方法的多載,這個多載不是本主題描述的特定多載。This code example uses an overload of this overloaded method that is different from the specific overload that this topic describes. 若要擴充範例以符合本主題內容,請以具有適當數值類型的項目取代來源序列的項目。To extend the example to this topic, substitute the elements of the source sequence with elements of the appropriate numerical type.

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

如果 source 不包含任何元素,Sum(IEnumerable<Decimal>) 方法會傳回零。The Sum(IEnumerable<Decimal>) method returns zero if source contains no elements.

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

Sum(IEnumerable<Nullable<Decimal>>)

計算可為 Null 之 Decimal 值序列的總和。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<Nullable<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>>

要計算總和之可為 Null 的 Decimal 值序列。A sequence of nullable Decimal values to calculate the sum of.

Returns

Nullable<Decimal>

序列中值的總合。The sum of the values in the sequence.

Exceptions

sourcenullsource is null.

總和大於 MaxValueThe sum is larger than MaxValue.

Examples

下列程式碼範例示範如何使用 Sum(IEnumerable<Nullable<Single>>) 來加總序列的值。The following code example demonstrates how to use Sum(IEnumerable<Nullable<Single>>) to sum the values of a sequence.

Note

這個程式碼範例會使用此多載方法的多載,這個多載不是本主題描述的特定多載。This code example uses an overload of this overloaded method that is different from the specific overload that this topic describes. 若要擴充範例以符合本主題內容,請以具有適當數值類型的項目取代來源序列的項目。To extend the example to this topic, substitute the elements of the source sequence with elements of the appropriate numerical type.

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

如果 source 未包含任何元素,這個方法會傳回零。This method returns zero if source contains no elements.

結果不是開頭包含 null的值。The result doesnot include values that are null.

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

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

計算在輸入序列中各項目上叫用轉換函式後所取得之 Single 值序列的總和。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

source 項目的類型。The type of the elements of source.

Parameters

source
IEnumerable<TSource>

用來計算總和的值序列。A sequence of values that are used to calculate a sum.

selector
Func<TSource,Single>

要套用至每個項目的轉換函式。A transform function to apply to each element.

Returns

Single

預計值的總合。The sum of the projected values.

Exceptions

sourceselectornullsource or selector is null.

Examples

下列程式碼範例示範如何使用 Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) 來加總序列的預測值。The following code example demonstrates how to use Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) to sum the projected values of a sequence.

Note

這個程式碼範例會使用此多載方法的多載,這個多載不是本主題描述的特定多載。This code example uses an overload of this overloaded method that is different from the specific overload that this topic describes. 若要將此範例延伸到本主題中使用,請變更 selector 函式的主體。To extend the example to this topic, 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

如果 source 不包含任何元素,Sum<TSource>(IEnumerable<TSource>, Func<TSource,Single>) 方法會傳回零。The Sum<TSource>(IEnumerable<TSource>, Func<TSource,Single>) method returns zero if source contains no elements.

如果您提供 selector的函式,將 source 的成員投射至數數值型別(特別是 Single),則可以將此方法套用至任意值的序列。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.

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

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

計算在輸入序列中各項目上叫用轉換函式後所取得可為 Null 之 Single 值的總和。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,Nullable<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

source 項目的類型。The type of the elements of source.

Parameters

source
IEnumerable<TSource>

用來計算總和的值序列。A sequence of values that are used to calculate a sum.

selector
Func<TSource,Nullable<Single>>

要套用至每個項目的轉換函式。A transform function to apply to each element.

Returns

Nullable<Single>

預計值的總合。The sum of the projected values.

Exceptions

sourceselectornullsource or selector is null.

Examples

下列程式碼範例示範如何使用 Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) 來加總序列的預測值。The following code example demonstrates how to use Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) to sum the projected values of a sequence.

Note

這個程式碼範例會使用此多載方法的多載,這個多載不是本主題描述的特定多載。This code example uses an overload of this overloaded method that is different from the specific overload that this topic describes. 若要將此範例延伸到本主題中使用,請變更 selector 函式的主體。To extend the example to this topic, 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

如果 source 未包含任何元素,這個方法會傳回零。This method returns zero if source contains no elements.

結果不包含 null的值。The result does not include values that are null.

如果您提供 selector的函式,將 source 的成員投射到數數值型別中,特別是在C# Visual Basic 中 Nullable<Single>Nullable(Of Single),您可以將此方法套用至任意值的序列。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.

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

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

計算在輸入序列中各項目上叫用轉換函式後所取得可為 Null 之 Int64 值的總和。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,Nullable<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

source 項目的類型。The type of the elements of source.

Parameters

source
IEnumerable<TSource>

用來計算總和的值序列。A sequence of values that are used to calculate a sum.

selector
Func<TSource,Nullable<Int64>>

要套用至每個項目的轉換函式。A transform function to apply to each element.

Returns

Nullable<Int64>

預計值的總合。The sum of the projected values.

Exceptions

sourceselectornullsource or selector is null.

總和大於 MaxValueThe sum is larger than MaxValue.

Examples

下列程式碼範例示範如何使用 Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) 來加總序列的預測值。The following code example demonstrates how to use Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) to sum the projected values of a sequence.

Note

這個程式碼範例會使用此多載方法的多載,這個多載不是本主題描述的特定多載。This code example uses an overload of this overloaded method that is different from the specific overload that this topic describes. 若要將此範例延伸到本主題中使用,請變更 selector 函式的主體。To extend the example to this topic, 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

如果 source 未包含任何元素,這個方法會傳回零。This method returns zero if source contains no elements.

結果不包含 null的值。The result does not include values that are null.

如果您提供函式 selector,將 source 的成員投射至數數值型別,特別是在C#中 Nullable<Int64>Nullable(Of Int64),則可以將此方法套用至任意值的序列 Visual BasicYou 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

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

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

計算在輸入序列中各項目上叫用轉換函式後所取得可為 Null 之 Int32 值的總和。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,Nullable<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

source 項目的類型。The type of the elements of source.

Parameters

source
IEnumerable<TSource>

用來計算總和的值序列。A sequence of values that are used to calculate a sum.

selector
Func<TSource,Nullable<Int32>>

要套用至每個項目的轉換函式。A transform function to apply to each element.

Returns

Nullable<Int32>

預計值的總合。The sum of the projected values.

Exceptions

sourceselectornullsource or selector is null.

總和大於 MaxValueThe sum is larger than MaxValue.

Examples

下列程式碼範例示範如何使用 Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) 來加總序列的預測值。The following code example demonstrates how to use Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) to sum the projected values of a sequence.

Note

這個程式碼範例會使用此多載方法的多載,這個多載不是本主題描述的特定多載。This code example uses an overload of this overloaded method that is different from the specific overload that this topic describes. 若要將此範例延伸到本主題中使用,請變更 selector 函式的主體。To extend the example to this topic, 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

如果 source 未包含任何元素,這個方法會傳回零。This method returns zero if source contains no elements.

結果不包含 null的值。The result does not include values that are null.

如果您提供 selector的函式,將 source 的成員投射到數數值型別中,特別是在C# Visual Basic 中 Nullable<Int32>Nullable(Of Int32),您可以將此方法套用至任意值的序列。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.

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

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

計算在輸入序列中各項目上叫用轉換函式後所取得可為 Null 之 Double 值的總和。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,Nullable<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

source 項目的類型。The type of the elements of source.

Parameters

source
IEnumerable<TSource>

用來計算總和的值序列。A sequence of values that are used to calculate a sum.

selector
Func<TSource,Nullable<Double>>

要套用至每個項目的轉換函式。A transform function to apply to each element.

Returns

Nullable<Double>

預計值的總合。The sum of the projected values.

Exceptions

sourceselectornullsource or selector is null.

Examples

下列程式碼範例示範如何使用 Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) 來加總序列的預測值。The following code example demonstrates how to use Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) to sum the projected values of a sequence.

Note

這個程式碼範例會使用此多載方法的多載,這個多載不是本主題描述的特定多載。This code example uses an overload of this overloaded method that is different from the specific overload that this topic describes. 若要將此範例延伸到本主題中使用,請變更 selector 函式的主體。To extend the example to this topic, 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

如果 source 未包含任何元素,這個方法會傳回零。This method returns zero if source contains no elements.

結果不包含 null的值。The result does not include values that are null.

如果您提供 selector的函式,將 source 的成員投射到數數值型別中,特別是在C# Visual Basic 中 Nullable<Double>Nullable(Of Double),您可以將此方法套用至任意值的序列。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.

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

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

計算在輸入序列中各項目上叫用轉換函式後所取得可為 Null 之 Decimal 值的總和。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,Nullable<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

source 項目的類型。The type of the elements of source.

Parameters

source
IEnumerable<TSource>

用來計算總和的值序列。A sequence of values that are used to calculate a sum.

selector
Func<TSource,Nullable<Decimal>>

要套用至每個項目的轉換函式。A transform function to apply to each element.

Returns

Nullable<Decimal>

預計值的總合。The sum of the projected values.

Exceptions

sourceselectornullsource or selector is null.

總和大於 MaxValueThe sum is larger than MaxValue.

Examples

下列程式碼範例示範如何使用 Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) 來加總序列的預測值。The following code example demonstrates how to use Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) to sum the projected values of a sequence.

Note

這個程式碼範例會使用此多載方法的多載,這個多載不是本主題描述的特定多載。This code example uses an overload of this overloaded method that is different from the specific overload that this topic describes. 若要將此範例延伸到本主題中使用,請變更 selector 函式的主體。To extend the example to this topic, 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

如果 source 未包含任何元素,這個方法會傳回零。This method returns zero if source contains no elements.

結果不包含 null的值。The result does not included values that are null.

如果您提供 selector的函式,將 source 的成員投射到數數值型別中,特別是在C# Visual Basic 中 Nullable<Decimal>Nullable(Of Decimal),您可以將此方法套用至任意值的序列。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.

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

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

計算在輸入序列中各項目上叫用轉換函式後所取得之 Int64 值序列的總和。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

source 項目的類型。The type of the elements of source.

Parameters

source
IEnumerable<TSource>

用來計算總和的值序列。A sequence of values that are used to calculate a sum.

selector
Func<TSource,Int64>

要套用至每個項目的轉換函式。A transform function to apply to each element.

Returns

Int64

預計值的總合。The sum of the projected values.

Exceptions

sourceselectornullsource or selector is null.

總和大於 MaxValueThe sum is larger than MaxValue.

Examples

下列程式碼範例示範如何使用 Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) 來加總序列的預測值。The following code example demonstrates how to use Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) to sum the projected values of a sequence.

Note

這個程式碼範例會使用此多載方法的多載,這個多載不是本主題描述的特定多載。This code example uses an overload of this overloaded method that is different from the specific overload that this topic describes. 若要將此範例延伸到本主題中使用,請變更 selector 函式的主體。To extend the example to this topic, 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

如果 source 未包含任何元素,這個方法會傳回零。This method returns zero if source contains no elements.

如果您提供 selector的函式,將 source 的成員投射至數數值型別(特別是 Int64),則可以將此方法套用至任意值的序列。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.

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

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

計算在輸入序列中各項目上叫用轉換函式後所取得之 Int32 值序列的總和。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

source 項目的類型。The type of the elements of source.

Parameters

source
IEnumerable<TSource>

用來計算總和的值序列。A sequence of values that are used to calculate a sum.

selector
Func<TSource,Int32>

要套用至每個項目的轉換函式。A transform function to apply to each element.

Returns

Int32

預計值的總合。The sum of the projected values.

Exceptions

sourceselectornullsource or selector is null.

總和大於 MaxValueThe sum is larger than MaxValue.

Examples

下列程式碼範例示範如何使用 Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) 來加總序列的預測值。The following code example demonstrates how to use Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) to sum the projected values of a sequence.

Note

這個程式碼範例會使用此多載方法的多載,這個多載不是本主題描述的特定多載。This code example uses an overload of this overloaded method that is different from the specific overload that this topic describes. 若要將此範例延伸到本主題中使用,請變更 selector 函式的主體。To extend the example to this topic, 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

如果 source 未包含任何元素,這個方法會傳回零。This method returns zero if source contains no elements.

如果您提供 selector的函式,將 source 的成員投射至數數值型別(特別是 Int32),則可以將此方法套用至任意值的序列。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.

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

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

計算在輸入序列中各項目上叫用轉換函式後所取得之 Double 值序列的總和。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

source 項目的類型。The type of the elements of source.

Parameters

source
IEnumerable<TSource>

用來計算總和的值序列。A sequence of values that are used to calculate a sum.

selector
Func<TSource,Double>

要套用至每個項目的轉換函式。A transform function to apply to each element.

Returns

Double

預計值的總合。The sum of the projected values.

Exceptions

sourceselectornullsource or selector is null.

Examples

下列程式碼範例示範如何使用 Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) 來加總序列的預測值。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

如果 source 未包含任何元素,這個方法會傳回零。This method returns zero if source contains no elements.

如果您提供 selector的函式,將 source 的成員投射至數數值型別(特別是 Double),則可以將此方法套用至任意值的序列。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.

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

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

計算在輸入序列中各項目上叫用轉換函式後所取得之 Decimal 值序列的總和。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

source 項目的類型。The type of the elements of source.

Parameters

source
IEnumerable<TSource>

用來計算總和的值序列。A sequence of values that are used to calculate a sum.

selector
Func<TSource,Decimal>

要套用至每個項目的轉換函式。A transform function to apply to each element.

Returns

Decimal

預計值的總合。The sum of the projected values.

Exceptions

sourceselectornullsource or selector is null.

總和大於 MaxValueThe sum is larger than MaxValue.

Examples

下列程式碼範例示範如何使用 Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) 來加總序列的預測值。The following code example demonstrates how to use Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) to sum the projected values of a sequence.

Note

這個程式碼範例會使用此多載方法的多載,這個多載不是本主題描述的特定多載。This code example uses an overload of this overloaded method that is different from the specific overload that this topic describes. 若要將此範例延伸到本主題中使用,請變更 selector 函式的主體。To extend the example to this topic, 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

如果 source 未包含任何元素,這個方法會傳回零。This method returns zero if source contains no elements.

如果您提供 selector的函式,將 source 的成員投射至數數值型別(特別是 Decimal),則可以將此方法套用至任意值的序列。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.

在 Visual Basic 查詢運算式語法中,Aggregate Into Sum() 子句會轉譯為 Sum的調用。In Visual Basic query expression syntax, an Aggregate Into Sum() clause translates to an invocation of Sum.

See also

Applies to