AsyncEnumerable.ElementAtOrDefaultAsync Method
Definition
Important
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Overloads
| ElementAtOrDefaultAsync<TSource>(IAsyncEnumerable<TSource>, Int32, CancellationToken) |
Returns the element at a specified index in a sequence, or a default value if the index is out of range. |
| ElementAtOrDefaultAsync<TSource>(IAsyncEnumerable<TSource>, Index, CancellationToken) |
Returns the element at a specified index in a sequence or a default value if the index is out of range. |
ElementAtOrDefaultAsync<TSource>(IAsyncEnumerable<TSource>, Int32, CancellationToken)
- Source:
- ElementAtAsync.cs
Returns the element at a specified index in a sequence, or a default value if the index is out of range.
public static System.Threading.Tasks.ValueTask<TSource?> ElementAtOrDefaultAsync<TSource>(this System.Collections.Generic.IAsyncEnumerable<TSource> source, int index, System.Threading.CancellationToken cancellationToken = default);static member ElementAtOrDefaultAsync : System.Collections.Generic.IAsyncEnumerable<'Source> * int * System.Threading.CancellationToken -> System.Threading.Tasks.ValueTask<'Source><Extension()>
Public Function ElementAtOrDefaultAsync(Of TSource) (source As IAsyncEnumerable(Of TSource), index As Integer, Optional cancellationToken As CancellationToken = Nothing) As ValueTask(Of TSource)Type Parameters
- TSource
The type of the elements of source.
Parameters
- source
- IAsyncEnumerable<TSource>
An IAsyncEnumerable<T> to return an element from.
- index
- Int32
The index of the element to retrieve, which is either from the beginning or the end of the sequence.
- cancellationToken
- CancellationToken
The CancellationToken to monitor for cancellation requests. The default is None.
Returns
The default value of TSource if index is outside the bounds of the source sequence; otherwise, the
element at the specified position in the source sequence.
Exceptions
source is null.
Applies to
ElementAtOrDefaultAsync<TSource>(IAsyncEnumerable<TSource>, Index, CancellationToken)
- Source:
- ElementAtAsync.cs
Returns the element at a specified index in a sequence or a default value if the index is out of range.
public static System.Threading.Tasks.ValueTask<TSource?> ElementAtOrDefaultAsync<TSource>(this System.Collections.Generic.IAsyncEnumerable<TSource> source, Index index, System.Threading.CancellationToken cancellationToken = default);static member ElementAtOrDefaultAsync : System.Collections.Generic.IAsyncEnumerable<'Source> * Index * System.Threading.CancellationToken -> System.Threading.Tasks.ValueTask<'Source><Extension()>
Public Function ElementAtOrDefaultAsync(Of TSource) (source As IAsyncEnumerable(Of TSource), index As Index, Optional cancellationToken As CancellationToken = Nothing) As ValueTask(Of TSource)Type Parameters
- TSource
The type of the elements of source.
Parameters
- source
- IAsyncEnumerable<TSource>
An IAsyncEnumerable<T> to return an element from.
- index
- Index
The index of the element to retrieve, which is either from the start or the end.
- cancellationToken
- CancellationToken
The token to monitor for cancellation requests. The default value is None.
Returns
default if index is outside the bounds of the source sequence; otherwise, the element at the specified position in the source sequence.
Exceptions
source is null.
Remarks
If the type of source implements IList<T>, that implementation is used to obtain the element at the specified index. Otherwise, this method obtains the specified element.
The default value for reference and nullable types is null.
