Pairwise Method (source, resultSelector)

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.

Declaration Syntax

Visual Basic

Visual C++

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
)

Generic Template Parameters

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

Parameters

source (IEnumerable<(Of <(<'TSource>)>)>): The source sequence.

resultSelector (Func<(Of <(<'TSource, TSource, TResult>)>)>): A transform function to apply to each pair of sequence.

Return Value

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<(Of <(<'TSource>)>)>. When you use instance method syntax to call this method, omit the first parameter.

Remarks

This operator uses deferred execution and streams its results.

Examples

	Copy
int[] numbers = { 123, 456, 789 }; IEnumerable<int> result = numbers.Pairwise(5, (a, b) => a + b);

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

Assembly: MoreLinq (Module: MoreLinq.dll) Version: 1.0.16006.0 (1.0.16006.1845)