Enumerable.Average 方法

定義

計算數值序列的平均值。Computes the average of a sequence of numeric values.

多載

Average(IEnumerable<Single>)

計算 Single 值序列的平均值。Computes the average of a sequence of Single values.

Average(IEnumerable<Nullable<Single>>)

計算可為 Null 之 Single 值序列的平均值。Computes the average of a sequence of nullable Single values.

Average(IEnumerable<Nullable<Int64>>)

計算可為 Null 之 Int64 值序列的平均值。Computes the average of a sequence of nullable Int64 values.

Average(IEnumerable<Nullable<Int32>>)

計算可為 Null 之 Int32 值序列的平均值。Computes the average of a sequence of nullable Int32 values.

Average(IEnumerable<Nullable<Double>>)

計算可為 Null 之 Double 值序列的平均值。Computes the average of a sequence of nullable Double values.

Average(IEnumerable<Int64>)

計算 Int64 值序列的平均值。Computes the average of a sequence of Int64 values.

Average(IEnumerable<Int32>)

計算 Int32 值序列的平均值。Computes the average of a sequence of Int32 values.

Average(IEnumerable<Double>)

計算 Double 值序列的平均值。Computes the average of a sequence of Double values.

Average(IEnumerable<Decimal>)

計算 Decimal 值序列的平均值。Computes the average of a sequence of Decimal values.

Average(IEnumerable<Nullable<Decimal>>)

計算可為 Null 之 Decimal 值序列的平均值。Computes the average of a sequence of nullable Decimal values.

Average<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 值的平均值。Computes the average of a sequence of nullable Int32 values that are obtained by invoking a transform function on each element of the input sequence.

Average<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 值序列的平均值。Computes the average of a sequence of Single values that are obtained by invoking a transform function on each element of the input sequence.

Average<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 值的平均值。Computes the average of a sequence of nullable Single values that are obtained by invoking a transform function on each element of the input sequence.

Average<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 值的平均值。Computes the average of a sequence of nullable Int64 values that are obtained by invoking a transform function on each element of the input sequence.

Average<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 值的平均值。Computes the average of a sequence of nullable Double values that are obtained by invoking a transform function on each element of the input sequence.

Average<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 值的平均值。Computes the average of a sequence of nullable Decimal values that are obtained by invoking a transform function on each element of the input sequence.

Average<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 值序列的平均值。Computes the average of a sequence of Int64 values that are obtained by invoking a transform function on each element of the input sequence.

Average<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 值序列的平均值。Computes the average of a sequence of Int32 values that are obtained by invoking a transform function on each element of the input sequence.

Average<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 值序列的平均值。Computes the average of a sequence of Double values that are obtained by invoking a transform function on each element of the input sequence.

Average<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 值序列的平均值。Computes the average of a sequence of Decimal values that are obtained by invoking a transform function on each element of the input sequence.

Average(IEnumerable<Single>)

計算 Single 值序列的平均值。Computes the average of a sequence of Single values.

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

參數

source
IEnumerable<Single>

要計算平均值的 Single 值序列。A sequence of Single values to calculate the average of.

傳回

值序列的平均。The average of the sequence of values.

例外狀況

sourcenullsource is null.

source 沒有包含任何項目。source contains no elements.

範例

下列程式碼範例示範如何使用 Average(IEnumerable<Int32>) 來計算平均值。The following code example demonstrates how to use Average(IEnumerable<Int32>) to calculate an average.

注意

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<int> grades = new List<int> { 78, 92, 100, 37, 81 };

double average = grades.Average();

Console.WriteLine("The average grade is {0}.", average);

// This code produces the following output:
//
// The average grade is 77.6.
' Create a list of integers.
Dim grades As New List(Of Integer)(New Integer() {78, 92, 100, 37, 81})

' Determine the average value in the list.
Dim avg As Double = grades.Average()

' Display the output.
Console.WriteLine($"The average grade is {avg}")

' This code produces the following output:
'
' The average grade is 77.6

備註

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

另請參閱

Average(IEnumerable<Nullable<Single>>)

計算可為 Null 之 Single 值序列的平均值。Computes the average of a sequence of nullable Single values.

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

參數

source
IEnumerable<Nullable<Single>>

要計算其平均值的可為 Null 之 Single 值的序列。A sequence of nullable Single values to calculate the average of.

傳回

值序列的平均值,或者,如果來源序列是空的或只包含 null 值,則為 nullThe average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

例外狀況

sourcenullsource is null.

範例

下列程式碼範例示範如何使用 Average(IEnumerable<Nullable<Int64>>) 來計算平均值。The following code example demonstrates how to use Average(IEnumerable<Nullable<Int64>>) to calculate an average.

注意

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.

long?[] longs = { null, 10007L, 37L, 399846234235L };

double? average = longs.Average();

Console.WriteLine("The average is {0}.", average);

// This code produces the following output:
//
// The average is 133282081426.333.
' Create an array of nullable long values.
Dim longs() As Nullable(Of Long) = {Nothing, 10007L, 37L, 399846234235L}

' Determine the average value in the array.
Dim avg As Nullable(Of Double) = longs.Average()

' Display the output.
Console.WriteLine($"The average is {avg}")

' This code produces the following output:
'
' The average is 133282081426.333

備註

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

另請參閱

Average(IEnumerable<Nullable<Int64>>)

計算可為 Null 之 Int64 值序列的平均值。Computes the average of a sequence of nullable Int64 values.

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

參數

source
IEnumerable<Nullable<Int64>>

要計算其平均值的可為 Null 之 Int64 值的序列。A sequence of nullable Int64 values to calculate the average of.

傳回

值序列的平均值,或者,如果來源序列是空的或只包含 null 值,則為 nullThe average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

例外狀況

sourcenullsource is null.

序列中項目的總和大於 MaxValueThe sum of the elements in the sequence is larger than MaxValue.

範例

下列程式碼範例示範如何使用 Average(IEnumerable<Nullable<Int64>>) 來計算平均值。The following code example demonstrates how to use Average(IEnumerable<Nullable<Int64>>) to calculate an average.

long?[] longs = { null, 10007L, 37L, 399846234235L };

double? average = longs.Average();

Console.WriteLine("The average is {0}.", average);

// This code produces the following output:
//
// The average is 133282081426.333.
' Create an array of nullable long values.
Dim longs() As Nullable(Of Long) = {Nothing, 10007L, 37L, 399846234235L}

' Determine the average value in the array.
Dim avg As Nullable(Of Double) = longs.Average()

' Display the output.
Console.WriteLine($"The average is {avg}")

' This code produces the following output:
'
' The average is 133282081426.333

備註

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

另請參閱

Average(IEnumerable<Nullable<Int32>>)

計算可為 Null 之 Int32 值序列的平均值。Computes the average of a sequence of nullable Int32 values.

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

參數

source
IEnumerable<Nullable<Int32>>

要計算其平均值的可為 Null 之 Int32 值的序列。A sequence of nullable Int32 values to calculate the average of.

傳回

值序列的平均值,或者,如果來源序列是空的或只包含 null 值,則為 nullThe average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

例外狀況

sourcenullsource is null.

序列中項目的總和大於 MaxValueThe sum of the elements in the sequence is larger than MaxValue.

範例

下列程式碼範例示範如何使用 Average(IEnumerable<Nullable<Int64>>) 來計算平均值。The following code example demonstrates how to use Average(IEnumerable<Nullable<Int64>>) to calculate an average.

注意

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.

long?[] longs = { null, 10007L, 37L, 399846234235L };

double? average = longs.Average();

Console.WriteLine("The average is {0}.", average);

// This code produces the following output:
//
// The average is 133282081426.333.
' Create an array of nullable long values.
Dim longs() As Nullable(Of Long) = {Nothing, 10007L, 37L, 399846234235L}

' Determine the average value in the array.
Dim avg As Nullable(Of Double) = longs.Average()

' Display the output.
Console.WriteLine($"The average is {avg}")

' This code produces the following output:
'
' The average is 133282081426.333

備註

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

另請參閱

Average(IEnumerable<Nullable<Double>>)

計算可為 Null 之 Double 值序列的平均值。Computes the average of a sequence of nullable Double values.

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

參數

source
IEnumerable<Nullable<Double>>

要計算其平均值的可為 Null 之 Double 值的序列。A sequence of nullable Double values to calculate the average of.

傳回

值序列的平均值,或者,如果來源序列是空的或只包含 null 值,則為 nullThe average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

例外狀況

sourcenullsource is null.

範例

下列程式碼範例示範如何使用 Average(IEnumerable<Nullable<Int64>>) 來計算平均值。The following code example demonstrates how to use Average(IEnumerable<Nullable<Int64>>) to calculate an average.

注意

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.

long?[] longs = { null, 10007L, 37L, 399846234235L };

double? average = longs.Average();

Console.WriteLine("The average is {0}.", average);

// This code produces the following output:
//
// The average is 133282081426.333.
' Create an array of nullable long values.
Dim longs() As Nullable(Of Long) = {Nothing, 10007L, 37L, 399846234235L}

' Determine the average value in the array.
Dim avg As Nullable(Of Double) = longs.Average()

' Display the output.
Console.WriteLine($"The average is {avg}")

' This code produces the following output:
'
' The average is 133282081426.333

備註

如果元素的總和太大,而無法表示為 Double,這個方法會傳回正數或負無限大。If the sum of the elements is too large to represent as a Double, this method returns positive or negative infinity.

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

另請參閱

Average(IEnumerable<Int64>)

計算 Int64 值序列的平均值。Computes the average of a sequence of Int64 values.

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

參數

source
IEnumerable<Int64>

要計算平均值的 Int64 值序列。A sequence of Int64 values to calculate the average of.

傳回

值序列的平均。The average of the sequence of values.

例外狀況

sourcenullsource is null.

source 沒有包含任何項目。source contains no elements.

範例

下列程式碼範例示範如何使用 Average(IEnumerable<Int32>) 來計算平均值。The following code example demonstrates how to use Average(IEnumerable<Int32>) to calculate an average.

注意

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<int> grades = new List<int> { 78, 92, 100, 37, 81 };

double average = grades.Average();

Console.WriteLine("The average grade is {0}.", average);

// This code produces the following output:
//
// The average grade is 77.6.
' Create a list of integers.
Dim grades As New List(Of Integer)(New Integer() {78, 92, 100, 37, 81})

' Determine the average value in the list.
Dim avg As Double = grades.Average()

' Display the output.
Console.WriteLine($"The average grade is {avg}")

' This code produces the following output:
'
' The average grade is 77.6

備註

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

另請參閱

Average(IEnumerable<Int32>)

計算 Int32 值序列的平均值。Computes the average of a sequence of Int32 values.

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

參數

source
IEnumerable<Int32>

要計算平均值的 Int32 值序列。A sequence of Int32 values to calculate the average of.

傳回

值序列的平均。The average of the sequence of values.

例外狀況

sourcenullsource is null.

source 沒有包含任何項目。source contains no elements.

範例

下列程式碼範例示範如何使用 Average(IEnumerable<Int32>) 來計算平均值。The following code example demonstrates how to use Average(IEnumerable<Int32>) to calculate an average.

List<int> grades = new List<int> { 78, 92, 100, 37, 81 };

double average = grades.Average();

Console.WriteLine("The average grade is {0}.", average);

// This code produces the following output:
//
// The average grade is 77.6.
' Create a list of integers.
Dim grades As New List(Of Integer)(New Integer() {78, 92, 100, 37, 81})

' Determine the average value in the list.
Dim avg As Double = grades.Average()

' Display the output.
Console.WriteLine($"The average grade is {avg}")

' This code produces the following output:
'
' The average grade is 77.6

備註

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

另請參閱

Average(IEnumerable<Double>)

計算 Double 值序列的平均值。Computes the average of a sequence of Double values.

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

參數

source
IEnumerable<Double>

要計算平均值的 Double 值序列。A sequence of Double values to calculate the average of.

傳回

值序列的平均。The average of the sequence of values.

例外狀況

sourcenullsource is null.

source 沒有包含任何項目。source contains no elements.

範例

下列程式碼範例示範如何使用 Average(IEnumerable<Int32>) 來計算平均值。The following code example demonstrates how to use Average(IEnumerable<Int32>) to calculate an average.

注意

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<int> grades = new List<int> { 78, 92, 100, 37, 81 };

double average = grades.Average();

Console.WriteLine("The average grade is {0}.", average);

// This code produces the following output:
//
// The average grade is 77.6.
' Create a list of integers.
Dim grades As New List(Of Integer)(New Integer() {78, 92, 100, 37, 81})

' Determine the average value in the list.
Dim avg As Double = grades.Average()

' Display the output.
Console.WriteLine($"The average grade is {avg}")

' This code produces the following output:
'
' The average grade is 77.6

備註

如果元素的總和太大,而無法表示為 Double,這個方法會傳回正數或負無限大。If the sum of the elements is too large to represent as a Double, this method returns positive or negative infinity.

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

另請參閱

Average(IEnumerable<Decimal>)

計算 Decimal 值序列的平均值。Computes the average of a sequence of Decimal values.

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

參數

source
IEnumerable<Decimal>

要計算平均值的 Decimal 值序列。A sequence of Decimal values to calculate the average of.

傳回

值序列的平均。The average of the sequence of values.

例外狀況

sourcenullsource is null.

source 沒有包含任何項目。source contains no elements.

範例

下列程式碼範例示範如何使用 Average(IEnumerable<Int32>) 來計算值序列的平均值。The following code example demonstrates how to use Average(IEnumerable<Int32>) to calculate the average of a sequence of values.

注意

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<int> grades = new List<int> { 78, 92, 100, 37, 81 };

double average = grades.Average();

Console.WriteLine("The average grade is {0}.", average);

// This code produces the following output:
//
// The average grade is 77.6.
' Create a list of integers.
Dim grades As New List(Of Integer)(New Integer() {78, 92, 100, 37, 81})

' Determine the average value in the list.
Dim avg As Double = grades.Average()

' Display the output.
Console.WriteLine($"The average grade is {avg}")

' This code produces the following output:
'
' The average grade is 77.6

備註

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

另請參閱

Average(IEnumerable<Nullable<Decimal>>)

計算可為 Null 之 Decimal 值序列的平均值。Computes the average of a sequence of nullable Decimal values.

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

參數

source
IEnumerable<Nullable<Decimal>>

要計算其平均值的可為 Null 之 Decimal 值的序列。A sequence of nullable Decimal values to calculate the average of.

傳回

值序列的平均值,或者,如果來源序列是空的或只包含 null 值,則為 nullThe average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

例外狀況

sourcenullsource is null.

序列中項目的總和大於 MaxValueThe sum of the elements in the sequence is larger than MaxValue.

範例

下列程式碼範例示範如何使用 Average(IEnumerable<Nullable<Int64>>) 來計算平均值。The following code example demonstrates how to use Average(IEnumerable<Nullable<Int64>>) to calculate an average.

注意

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.

long?[] longs = { null, 10007L, 37L, 399846234235L };

double? average = longs.Average();

Console.WriteLine("The average is {0}.", average);

// This code produces the following output:
//
// The average is 133282081426.333.
' Create an array of nullable long values.
Dim longs() As Nullable(Of Long) = {Nothing, 10007L, 37L, 399846234235L}

' Determine the average value in the array.
Dim avg As Nullable(Of Double) = longs.Average()

' Display the output.
Console.WriteLine($"The average is {avg}")

' This code produces the following output:
'
' The average is 133282081426.333

備註

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

另請參閱

Average<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 值的平均值。Computes the average of a 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<double> Average(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, Nullable<int>> ^ selector);
public static Nullable<double> Average<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,Nullable<int>> selector);
static member Average : seq<'Source> * Func<'Source, Nullable<int>> -> Nullable<double>
<Extension()>
Public Function Average(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Nullable(Of Integer))) As Nullable(Of Double)

類型參數

TSource

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

參數

source
IEnumerable<TSource>

要計算平均值的值序列。A sequence of values to calculate the average of.

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.

傳回

值序列的平均值,或者,如果來源序列是空的或只包含 null 值,則為 nullThe average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

例外狀況

sourceselectornullsource or selector is null.

序列中項目的總和大於 MaxValueThe sum of the elements in the sequence is larger than MaxValue.

範例

下列程式碼範例示範如何使用 Average<TSource>(IEnumerable<TSource>, Func<TSource,Int32>) 來計算平均值。The following code example demonstrates how to use Average<TSource>(IEnumerable<TSource>, Func<TSource,Int32>) to calculate an average.

注意

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.

string[] fruits = { "apple", "banana", "mango", "orange", "passionfruit", "grape" };

double average = fruits.Average(s => s.Length);

Console.WriteLine("The average string length is {0}.", average);

// This code produces the following output:
//
// The average string length is 6.5.
' Create an array of strings.
Dim fruits() As String =
{"apple", "banana", "mango", "orange", "passionfruit", "grape"}

' Determine the average length of the strings in the array.
Dim avg As Double = fruits.Average(Function(s) s.Length)

' Display the output.
Console.WriteLine($"The average string length is {avg}")

' This code produces the following output:
'
' The average string length is 6.5

備註

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

另請參閱

Average<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 值序列的平均值。Computes the average of a 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 Average(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, float> ^ selector);
public static float Average<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,float> selector);
static member Average : seq<'Source> * Func<'Source, single> -> single
<Extension()>
Public Function Average(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Single)) As Single

類型參數

TSource

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

參數

source
IEnumerable<TSource>

要計算平均值的值序列。A sequence of values to calculate the average of.

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.

傳回

值序列的平均。The average of the sequence of values.

例外狀況

sourceselectornullsource or selector is null.

source 沒有包含任何項目。source contains no elements.

範例

下列程式碼範例示範如何使用 Average<TSource>(IEnumerable<TSource>, Func<TSource,Int32>) 來計算平均值。The following code example demonstrates how to use Average<TSource>(IEnumerable<TSource>, Func<TSource,Int32>) to calculate an average.

注意

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.

string[] fruits = { "apple", "banana", "mango", "orange", "passionfruit", "grape" };

double average = fruits.Average(s => s.Length);

Console.WriteLine("The average string length is {0}.", average);

// This code produces the following output:
//
// The average string length is 6.5.
' Create an array of strings.
Dim fruits() As String =
{"apple", "banana", "mango", "orange", "passionfruit", "grape"}

' Determine the average length of the strings in the array.
Dim avg As Double = fruits.Average(Function(s) s.Length)

' Display the output.
Console.WriteLine($"The average string length is {avg}")

' This code produces the following output:
'
' The average string length is 6.5

備註

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

另請參閱

Average<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 值的平均值。Computes the average of a 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> Average(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, Nullable<float>> ^ selector);
public static Nullable<float> Average<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,Nullable<float>> selector);
static member Average : seq<'Source> * Func<'Source, Nullable<single>> -> Nullable<single>
<Extension()>
Public Function Average(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Nullable(Of Single))) As Nullable(Of Single)

類型參數

TSource

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

參數

source
IEnumerable<TSource>

要計算平均值的值序列。A sequence of values to calculate the average of.

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.

傳回

值序列的平均值,或者,如果來源序列是空的或只包含 null 值,則為 nullThe average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

例外狀況

sourceselectornullsource or selector is null.

範例

下列程式碼範例示範如何使用 Average<TSource>(IEnumerable<TSource>, Func<TSource,Int32>) 來計算平均值。The following code example demonstrates how to use Average<TSource>(IEnumerable<TSource>, Func<TSource,Int32>) to calculate an average.

注意

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.

string[] fruits = { "apple", "banana", "mango", "orange", "passionfruit", "grape" };

double average = fruits.Average(s => s.Length);

Console.WriteLine("The average string length is {0}.", average);

// This code produces the following output:
//
// The average string length is 6.5.
' Create an array of strings.
Dim fruits() As String =
{"apple", "banana", "mango", "orange", "passionfruit", "grape"}

' Determine the average length of the strings in the array.
Dim avg As Double = fruits.Average(Function(s) s.Length)

' Display the output.
Console.WriteLine($"The average string length is {avg}")

' This code produces the following output:
'
' The average string length is 6.5

備註

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

另請參閱

Average<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 值的平均值。Computes the average of a 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<double> Average(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, Nullable<long>> ^ selector);
public static Nullable<double> Average<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,Nullable<long>> selector);
static member Average : seq<'Source> * Func<'Source, Nullable<int64>> -> Nullable<double>
<Extension()>
Public Function Average(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Nullable(Of Long))) As Nullable(Of Double)

類型參數

TSource

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

參數

source
IEnumerable<TSource>

要計算平均值的值序列。A sequence of values to calculate the average of.

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.

傳回

值序列的平均值,或者,如果來源序列是空的或只包含 null 值,則為 nullThe average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

範例

下列程式碼範例示範如何使用 Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) 來計算平均值。The following code example demonstrates how to use Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) to calculate an average.

注意

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.

string[] numbers = { "10007", "37", "299846234235" };

double average = numbers.Average(num => Convert.ToInt64(num));

Console.WriteLine("The average is {0}.", average);

// This code produces the following output:
//
// The average is 99948748093.
' Create an array of strings.
Dim numbers() As String = {"10007", "37", "299846234235"}

' Determine the average number after converting each
' string to an Int64 value.
Dim avg As Double =
numbers.Average(Function(number) Convert.ToInt64(number))

' Display the output.
Console.WriteLine($"The average is {avg}")

' This code produces the following output:
'
' The average is 99948748093

備註

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

另請參閱

Average<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 值的平均值。Computes the average of a 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> Average(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, Nullable<double>> ^ selector);
public static Nullable<double> Average<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,Nullable<double>> selector);
static member Average : seq<'Source> * Func<'Source, Nullable<double>> -> Nullable<double>
<Extension()>
Public Function Average(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Nullable(Of Double))) As Nullable(Of Double)

類型參數

TSource

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

參數

source
IEnumerable<TSource>

要計算平均值的值序列。A sequence of values to calculate the average of.

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.

傳回

值序列的平均值,或者,如果來源序列是空的或只包含 null 值,則為 nullThe average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

例外狀況

sourceselectornullsource or selector is null.

範例

下列程式碼範例示範如何使用 Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) 來計算平均值。The following code example demonstrates how to use Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) to calculate an average.

注意

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.

string[] numbers = { "10007", "37", "299846234235" };

double average = numbers.Average(num => Convert.ToInt64(num));

Console.WriteLine("The average is {0}.", average);

// This code produces the following output:
//
// The average is 99948748093.
' Create an array of strings.
Dim numbers() As String = {"10007", "37", "299846234235"}

' Determine the average number after converting each
' string to an Int64 value.
Dim avg As Double =
numbers.Average(Function(number) Convert.ToInt64(number))

' Display the output.
Console.WriteLine($"The average is {avg}")

' This code produces the following output:
'
' The average is 99948748093

備註

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

另請參閱

Average<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 值的平均值。Computes the average of a 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> Average(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, Nullable<System::Decimal>> ^ selector);
public static Nullable<decimal> Average<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,Nullable<decimal>> selector);
static member Average : seq<'Source> * Func<'Source, Nullable<decimal>> -> Nullable<decimal>
<Extension()>
Public Function Average(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Nullable(Of Decimal))) As Nullable(Of Decimal)

類型參數

TSource

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

參數

source
IEnumerable<TSource>

要計算平均值的值序列。A sequence of values to calculate the average of.

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.

傳回

值序列的平均值,或者,如果來源序列是空的或只包含 null 值,則為 nullThe average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

例外狀況

sourceselectornullsource or selector is null.

序列中項目的總和大於 MaxValueThe sum of the elements in the sequence is larger than MaxValue.

範例

下列程式碼範例示範如何使用 Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) 來計算平均值。The following code example demonstrates how to use Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) to calculate an average.

注意

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.

string[] numbers = { "10007", "37", "299846234235" };

double average = numbers.Average(num => Convert.ToInt64(num));

Console.WriteLine("The average is {0}.", average);

// This code produces the following output:
//
// The average is 99948748093.
' Create an array of strings.
Dim numbers() As String = {"10007", "37", "299846234235"}

' Determine the average number after converting each
' string to an Int64 value.
Dim avg As Double =
numbers.Average(Function(number) Convert.ToInt64(number))

' Display the output.
Console.WriteLine($"The average is {avg}")

' This code produces the following output:
'
' The average is 99948748093

備註

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

另請參閱

Average<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 值序列的平均值。Computes the average of a 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 double Average(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, long> ^ selector);
public static double Average<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,long> selector);
static member Average : seq<'Source> * Func<'Source, int64> -> double
<Extension()>
Public Function Average(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Long)) As Double

類型參數

TSource

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

參數

source
IEnumerable<TSource>

要計算平均值的值序列。A sequence of values to calculate the average of.

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.

傳回

值序列的平均。The average of the sequence of values.

例外狀況

sourceselectornullsource or selector is null.

source 沒有包含任何項目。source contains no elements.

序列中項目的總和大於 MaxValueThe sum of the elements in the sequence is larger than MaxValue.

範例

下列程式碼範例示範如何使用 Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) 來計算平均值。The following code example demonstrates how to use Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) to calculate an average.

string[] numbers = { "10007", "37", "299846234235" };

double average = numbers.Average(num => Convert.ToInt64(num));

Console.WriteLine("The average is {0}.", average);

// This code produces the following output:
//
// The average is 99948748093.
' Create an array of strings.
Dim numbers() As String = {"10007", "37", "299846234235"}

' Determine the average number after converting each
' string to an Int64 value.
Dim avg As Double =
numbers.Average(Function(number) Convert.ToInt64(number))

' Display the output.
Console.WriteLine($"The average is {avg}")

' This code produces the following output:
'
' The average is 99948748093

備註

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

另請參閱

Average<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 值序列的平均值。Computes the average of a 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 double Average(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, int> ^ selector);
public static double Average<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,int> selector);
static member Average : seq<'Source> * Func<'Source, int> -> double
<Extension()>
Public Function Average(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Integer)) As Double

類型參數

TSource

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

參數

source
IEnumerable<TSource>

要計算平均值的值序列。A sequence of values to calculate the average of.

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.

傳回

值序列的平均。The average of the sequence of values.

例外狀況

sourceselectornullsource or selector is null.

source 沒有包含任何項目。source contains no elements.

序列中項目的總和大於 MaxValueThe sum of the elements in the sequence is larger than MaxValue.

範例

下列程式碼範例示範如何使用 Average<TSource>(IEnumerable<TSource>, Func<TSource,Int32>) 來計算平均值。The following code example demonstrates how to use Average<TSource>(IEnumerable<TSource>, Func<TSource,Int32>) to calculate an average.

string[] fruits = { "apple", "banana", "mango", "orange", "passionfruit", "grape" };

double average = fruits.Average(s => s.Length);

Console.WriteLine("The average string length is {0}.", average);

// This code produces the following output:
//
// The average string length is 6.5.
' Create an array of strings.
Dim fruits() As String =
{"apple", "banana", "mango", "orange", "passionfruit", "grape"}

' Determine the average length of the strings in the array.
Dim avg As Double = fruits.Average(Function(s) s.Length)

' Display the output.
Console.WriteLine($"The average string length is {avg}")

' This code produces the following output:
'
' The average string length is 6.5

備註

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

另請參閱

Average<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 值序列的平均值。Computes the average of a 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 Average(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, double> ^ selector);
public static double Average<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,double> selector);
static member Average : seq<'Source> * Func<'Source, double> -> double
<Extension()>
Public Function Average(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Double)) As Double

類型參數

TSource

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

參數

source
IEnumerable<TSource>

要計算平均值的值序列。A sequence of values to calculate the average of.

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.

傳回

值序列的平均。The average of the sequence of values.

例外狀況

sourceselectornullsource or selector is null.

source 沒有包含任何項目。source contains no elements.

範例

下列程式碼範例示範如何使用 Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) 來計算平均值。The following code example demonstrates how to use Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) to calculate an average.

注意

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.

string[] numbers = { "10007", "37", "299846234235" };

double average = numbers.Average(num => Convert.ToInt64(num));

Console.WriteLine("The average is {0}.", average);

// This code produces the following output:
//
// The average is 99948748093.
' Create an array of strings.
Dim numbers() As String = {"10007", "37", "299846234235"}

' Determine the average number after converting each
' string to an Int64 value.
Dim avg As Double =
numbers.Average(Function(number) Convert.ToInt64(number))

' Display the output.
Console.WriteLine($"The average is {avg}")

' This code produces the following output:
'
' The average is 99948748093

備註

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

另請參閱

Average<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 值序列的平均值。Computes the average of a 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 Average(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, System::Decimal> ^ selector);
public static decimal Average<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,decimal> selector);
static member Average : seq<'Source> * Func<'Source, decimal> -> decimal
<Extension()>
Public Function Average(Of TSource) (source As IEnumerable(Of TSource), selector As Func(Of TSource, Decimal)) As Decimal

類型參數

TSource

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

參數

source
IEnumerable<TSource>

用來計算平均值的值序列。A sequence of values that are used to calculate an average.

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.

傳回

值序列的平均。The average of the sequence of values.

例外狀況

sourceselectornullsource or selector is null.

source 沒有包含任何項目。source contains no elements.

序列中項目的總和大於 MaxValueThe sum of the elements in the sequence is larger than MaxValue.

範例

下列程式碼範例示範如何使用 Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) 來計算平均值。The following code example demonstrates how to use Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) to calculate an average.

注意

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.

string[] numbers = { "10007", "37", "299846234235" };

double average = numbers.Average(num => Convert.ToInt64(num));

Console.WriteLine("The average is {0}.", average);

// This code produces the following output:
//
// The average is 99948748093.
' Create an array of strings.
Dim numbers() As String = {"10007", "37", "299846234235"}

' Determine the average number after converting each
' string to an Int64 value.
Dim avg As Double =
numbers.Average(Function(number) Convert.ToInt64(number))

' Display the output.
Console.WriteLine($"The average is {avg}")

' This code produces the following output:
'
' The average is 99948748093

備註

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

另請參閱

適用於