Enumerable.Average Method

Reference

Definition

Namespace:: System.Linq

Assembly:: System.Linq.dll

Assembly:: System.Core.dll

Assembly:: netstandard.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Computes the average of a sequence of numeric values.

Overloads

Average(IEnumerable<Single>)	Computes the average of a sequence of Single values.
Average(IEnumerable<Nullable<Single>>)	Computes the average of a sequence of nullable Single values.
Average(IEnumerable<Nullable<Int64>>)	Computes the average of a sequence of nullable Int64 values.
Average(IEnumerable<Nullable<Int32>>)	Computes the average of a sequence of nullable Int32 values.
Average(IEnumerable<Nullable<Double>>)	Computes the average of a sequence of nullable Double values.
Average(IEnumerable<Double>)	Computes the average of a sequence of Double values.
Average(IEnumerable<Int64>)	Computes the average of a sequence of Int64 values.
Average(IEnumerable<Int32>)	Computes the average of a sequence of Int32 values.
Average(IEnumerable<Decimal>)	Computes the average of a sequence of Decimal values.
Average(IEnumerable<Nullable<Decimal>>)	Computes the average of a sequence of nullable Decimal values.
Average<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int32>>)	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>)	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<Int64>>)	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>>)	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<Single>>)	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,Int64>)	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>)	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>)	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>)	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<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Decimal>>)	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(IEnumerable<Single>)

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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

Parameters

source: IEnumerable<Single>

A sequence of Single values to calculate the average of.

Returns

Single

The average of the sequence of values.

Exceptions

ArgumentNullException

source is null.

InvalidOperationException

source contains no elements.

Remarks

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

Applies to

Average(IEnumerable<Nullable<Single>>)

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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 float? Average (this System.Collections.Generic.IEnumerable<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)

Parameters

source: IEnumerable<Nullable<Single>>

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

Returns

Nullable<Single>

The average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

Exceptions

ArgumentNullException

source is null.

Remarks

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

Applies to

Average(IEnumerable<Nullable<Int64>>)

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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 double? Average (this System.Collections.Generic.IEnumerable<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)

Parameters

source: IEnumerable<Nullable<Int64>>

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

Returns

Nullable<Double>

The average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

Exceptions

ArgumentNullException

source is null.

OverflowException

The sum of the elements in the sequence is larger than Int64.MaxValue.

Examples

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

Remarks

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

Applies to

Average(IEnumerable<Nullable<Int32>>)

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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 double? Average (this System.Collections.Generic.IEnumerable<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)

Parameters

source: IEnumerable<Nullable<Int32>>

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

Returns

Nullable<Double>

The average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

Exceptions

ArgumentNullException

source is null.

OverflowException

The sum of the elements in the sequence is larger than Int64.MaxValue.

Remarks

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

Applies to

Average(IEnumerable<Nullable<Double>>)

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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 double? Average (this System.Collections.Generic.IEnumerable<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)

Parameters

source: IEnumerable<Nullable<Double>>

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

Returns

Nullable<Double>

The average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

Exceptions

ArgumentNullException

source is null.

Remarks

If the sum of the elements is too large to represent as a Double, this method returns positive or negative infinity.

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

Applies to

Average(IEnumerable<Double>)

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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

Parameters

source: IEnumerable<Double>

A sequence of Double values to calculate the average of.

Returns

Double

The average of the sequence of values.

Exceptions

ArgumentNullException

source is null.

InvalidOperationException

source contains no elements.

Remarks

If the sum of the elements is too large to represent as a Double, this method returns positive or negative infinity.

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

Applies to

Average(IEnumerable<Int64>)

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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

Parameters

source: IEnumerable<Int64>

A sequence of Int64 values to calculate the average of.

Returns

Double

The average of the sequence of values.

Exceptions

ArgumentNullException

source is null.

InvalidOperationException

source contains no elements.

Remarks

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

Applies to

Average(IEnumerable<Int32>)

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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

Parameters

source: IEnumerable<Int32>

A sequence of Int32 values to calculate the average of.

Returns

Double

The average of the sequence of values.

Exceptions

ArgumentNullException

source is null.

InvalidOperationException

source contains no elements.

Examples

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

Remarks

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

Applies to

Average(IEnumerable<Decimal>)

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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

Parameters

source: IEnumerable<Decimal>

A sequence of Decimal values to calculate the average of.

Returns

Decimal

The average of the sequence of values.

Exceptions

ArgumentNullException

source is null.

InvalidOperationException

source contains no elements.

Remarks

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

Applies to

Average(IEnumerable<Nullable<Decimal>>)

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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 decimal? Average (this System.Collections.Generic.IEnumerable<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)

Parameters

source: IEnumerable<Nullable<Decimal>>

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

Returns

Nullable<Decimal>

The average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

Exceptions

ArgumentNullException

source is null.

OverflowException

The sum of the elements in the sequence is larger than Decimal.MaxValue.

Remarks

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

Applies to

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

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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 double? Average<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,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)

Type Parameters

TSource

The type of the elements of source.

Parameters

source: IEnumerable<TSource>

A sequence of values to calculate the average of.

selector: Func<TSource,Nullable<Int32>>

A transform function to apply to each element.

Returns

Nullable<Double>

The average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

Exceptions

ArgumentNullException

source or selector is null.

OverflowException

The sum of the elements in the sequence is larger than Int64.MaxValue.

Examples

The following code example demonstrates how to use Average<TSource>(IEnumerable<TSource>, Func<TSource,Int32>) to calculate an average.

Note

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

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

Remarks

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

Applies to

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

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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

Type Parameters

TSource

The type of the elements of source.

Parameters

source: IEnumerable<TSource>

A sequence of values to calculate the average of.

selector: Func<TSource,Single>

A transform function to apply to each element.

Returns

Single

The average of the sequence of values.

Exceptions

ArgumentNullException

source or selector is null.

InvalidOperationException

source contains no elements.

Examples

The following code example demonstrates how to use Average<TSource>(IEnumerable<TSource>, Func<TSource,Int32>) to calculate an average.

Note

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

Remarks

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

Applies to

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

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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 double? Average<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,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)

Type Parameters

TSource

The type of the elements of source.

Parameters

source: IEnumerable<TSource>

A sequence of values to calculate the average of.

selector: Func<TSource,Nullable<Int64>>

A transform function to apply to each element.

Returns

Nullable<Double>

The average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

Examples

The following code example demonstrates how to use Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) to calculate an average.

Note

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

double average = numbers.Average(num => long.Parse(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

Remarks

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

Applies to

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

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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 double? Average<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,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)

Type Parameters

TSource

The type of the elements of source.

Parameters

source: IEnumerable<TSource>

A sequence of values to calculate the average of.

selector: Func<TSource,Nullable<Double>>

A transform function to apply to each element.

Returns

Nullable<Double>

The average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

Exceptions

ArgumentNullException

source or selector is null.

Examples

The following code example demonstrates how to use Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) to calculate an average.

Note

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

double average = numbers.Average(num => long.Parse(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

Remarks

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

Applies to

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

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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 float? Average<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,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)

Type Parameters

TSource

The type of the elements of source.

Parameters

source: IEnumerable<TSource>

A sequence of values to calculate the average of.

selector: Func<TSource,Nullable<Single>>

A transform function to apply to each element.

Returns

Nullable<Single>

The average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

Exceptions

ArgumentNullException

source or selector is null.

Examples

The following code example demonstrates how to use Average<TSource>(IEnumerable<TSource>, Func<TSource,Int32>) to calculate an average.

Note

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

Remarks

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

Applies to

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

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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

Type Parameters

TSource

The type of the elements of source.

Parameters

source: IEnumerable<TSource>

A sequence of values to calculate the average of.

selector: Func<TSource,Int64>

A transform function to apply to each element.

Returns

Double

The average of the sequence of values.

Exceptions

ArgumentNullException

source or selector is null.

InvalidOperationException

source contains no elements.

OverflowException

The sum of the elements in the sequence is larger than Int64.MaxValue.

Examples

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 => long.Parse(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

Remarks

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

Applies to

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

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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

Type Parameters

TSource

The type of the elements of source.

Parameters

source: IEnumerable<TSource>

A sequence of values to calculate the average of.

selector: Func<TSource,Int32>

A transform function to apply to each element.

Returns

Double

The average of the sequence of values.

Exceptions

ArgumentNullException

source or selector is null.

InvalidOperationException

source contains no elements.

OverflowException

The sum of the elements in the sequence is larger than Int64.MaxValue.

Examples

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

Remarks

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

Applies to

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

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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

Type Parameters

TSource

The type of the elements of source.

Parameters

source: IEnumerable<TSource>

A sequence of values to calculate the average of.

selector: Func<TSource,Double>

A transform function to apply to each element.

Returns

Double

The average of the sequence of values.

Exceptions

ArgumentNullException

source or selector is null.

InvalidOperationException

source contains no elements.

Examples

The following code example demonstrates how to use Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) to calculate an average.

Note

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

double average = numbers.Average(num => long.Parse(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

Remarks

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

Applies to

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

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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

Type Parameters

TSource

The type of the elements of source.

Parameters

source: IEnumerable<TSource>

A sequence of values that are used to calculate an average.

selector: Func<TSource,Decimal>

A transform function to apply to each element.

Returns

Decimal

The average of the sequence of values.

Exceptions

ArgumentNullException

source or selector is null.

InvalidOperationException

source contains no elements.

OverflowException

The sum of the elements in the sequence is larger than Decimal.MaxValue.

Examples

The following code example demonstrates how to use Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) to calculate an average.

Note

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

double average = numbers.Average(num => long.Parse(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

Remarks

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

Applies to

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

Source:: Average.cs

Source:: Average.cs

Source:: Average.cs

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 decimal? Average<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,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)

Type Parameters

TSource

The type of the elements of source.

Parameters

source: IEnumerable<TSource>

A sequence of values to calculate the average of.

selector: Func<TSource,Nullable<Decimal>>

A transform function to apply to each element.

Returns

Nullable<Decimal>

The average of the sequence of values, or null if the source sequence is empty or contains only values that are null.

Exceptions

ArgumentNullException

source or selector is null.

OverflowException

The sum of the elements in the sequence is larger than Decimal.MaxValue.

Examples

The following code example demonstrates how to use Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) to calculate an average.

Note

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

double average = numbers.Average(num => long.Parse(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

Remarks

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

Applies to

Megosztás a következőn keresztül:

Enumerable.Average Method

Definition

Overloads

Average(IEnumerable<Single>)

Parameters

Returns

Exceptions

Remarks

See also

Applies to

Average(IEnumerable<Nullable<Single>>)

Parameters

Returns

Exceptions

Remarks

See also

Applies to

Average(IEnumerable<Nullable<Int64>>)

Parameters

Returns

Exceptions

Examples

Remarks

See also

Applies to

Average(IEnumerable<Nullable<Int32>>)

Parameters

Returns

Exceptions

Remarks

See also

Applies to

Average(IEnumerable<Nullable<Double>>)

Parameters

Returns

Exceptions

Remarks

See also

Applies to

Average(IEnumerable<Double>)

Parameters

Returns

Exceptions

Remarks

See also

Applies to

Average(IEnumerable<Int64>)

Parameters

Returns

Exceptions

Remarks

See also

Applies to

Average(IEnumerable<Int32>)

Parameters

Returns

Exceptions

Examples

Remarks

See also

Applies to

Average(IEnumerable<Decimal>)

Parameters

Returns

Exceptions

Remarks

See also

Applies to

Average(IEnumerable<Nullable<Decimal>>)

Parameters

Returns

Exceptions

Remarks

See also

Applies to

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

Type Parameters

Parameters

Returns