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Observable.Scan<TSource> Method (IObservable<TSource>, Func<TSource, TSource, TSource>)

Applies an accumulator function over an observable sequence and returns each intermediate result with the specified source and accumulator.

Namespace:  System.Reactive.Linq
Assembly:  System.Reactive (in System.Reactive.dll)


<ExtensionAttribute> _
Public Shared Function Scan(Of TSource) ( _
    source As IObservable(Of TSource), _
    accumulator As Func(Of TSource, TSource, TSource) _
) As IObservable(Of TSource)
Dim source As IObservable(Of TSource)
Dim accumulator As Func(Of TSource, TSource, TSource)
Dim returnValue As IObservable(Of TSource)

returnValue = source.Scan(accumulator)
public static IObservable<TSource> Scan<TSource>(
    this IObservable<TSource> source,
    Func<TSource, TSource, TSource> accumulator
generic<typename TSource>
static IObservable<TSource>^ Scan(
    IObservable<TSource>^ source, 
    Func<TSource, TSource, TSource>^ accumulator
static member Scan : 
        source:IObservable<'TSource> * 
        accumulator:Func<'TSource, 'TSource, 'TSource> -> IObservable<'TSource> 
JScript does not support generic types and methods.

Type Parameters

  • TSource
    The type of source.


  • accumulator
    Type: System.Func<TSource, TSource, TSource>
    An accumulator function to be invoked on each element.

Return Value

Type: System.IObservable<TSource>
An observable sequence containing the accumulated values.

Usage Note

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

See Also


Observable Class

Scan Overload

System.Reactive.Linq Namespace