Returns a sequence resulting from applying a function to each element in the source sequence and its predecessor, with the exception of the first element which is only returned as the predecessor of the second element.

Namespace: MoreLinq
Assembly: MoreLinq (in MoreLinq.dll) Version: 2.6.0

Syntax

C++

Copy

public static IEnumerable<TResult> Pairwise<TSource, TResult>(
	this IEnumerable<TSource> source,
	Func<TSource, TSource, TResult> resultSelector
)

<ExtensionAttribute>
Public Shared Function Pairwise(Of TSource, TResult) ( 
	source As IEnumerable(Of TSource),
	resultSelector As Func(Of TSource, TSource, TResult)
) As IEnumerable(Of TResult)

public:
[ExtensionAttribute]
generic<typename TSource, typename TResult>
static IEnumerable<TResult>^ Pairwise(
	IEnumerable<TSource>^ source, 
	Func<TSource, TSource, TResult>^ resultSelector
)

[<ExtensionAttribute>]
static member Pairwise : 
        source : IEnumerable<'TSource> * 
        resultSelector : Func<'TSource, 'TSource, 'TResult> -> IEnumerable<'TResult>

Parameters

source: Type: System.Collections.Generic.IEnumerable<TSource>
The source sequence.
resultSelector: Type: System.Func<TSource, TSource, TResult>
A transform function to apply to each pair of sequence.

Type Parameters

TSource: The type of the elements of source.
TResult: The type of the element of the returned sequence.

Return Value

Type: IEnumerable<TResult>
Returns the resulting sequence.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable<TSource>. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).

Remarks

This operator uses deferred execution and streams its results.

Examples

Copy

int[] numbers = { 123, 456, 789 };
IEnumerable<int> result = numbers.Pairwise((a, b) => a + b);

The result variable, when iterated over, will yield 579 and 1245, in turn.

Reference

MoreEnumerable Class

MoreLinq Namespace

MoreEnumerable.AddLanguageSpecificTextSet("LSTEC564424_0?cpp=::|nu=.");Pairwise<AddLanguageSpecificTextSet("LSTEC564424_1?cs=&lt;|vb=(Of |cpp=&lt;|fs=&lt;'|nu=(");TSource, TResult>AddLanguageSpecificTextSet("LSTEC564424_2?cs=&gt;|vb=)|cpp=&gt;|fs=&gt;|nu=)"); Method

Parameters

Type Parameters

Return Value

Usage Note

Reference

MoreEnumerable.Pairwise<TSource, TResult> Method