Returns the first element of the parallel sequence that satisfies a condition or a
default value if no such element is found.
Namespace:
System.Linq
Assembly:
System.Threading (in System.Threading.dll)
Syntax
| Visual Basic (Declaration) |
|---|
Public Shared Function FirstOrDefault(Of TSource) ( _
source As ParallelQuery(Of TSource), _
predicate As Func(Of TSource, Boolean) _
) As TSource |
| C# |
|---|
public static TSource FirstOrDefault<TSource>(
ParallelQuery<TSource> source,
Func<TSource, bool> predicate
)
|
Parameters
- source
- Type: System.Linq..::.ParallelQuery<(Of <(TSource>)>)
The sequence to return an element from.
- predicate
- Type: System..::.Func<(Of <(TSource, Boolean>)>)
A function to test each element for a condition.
Type Parameters
- TSource
- The type of the elements of source.
Return Value
default(TSource) if
source is empty or if no element passes the test
specified by predicate; otherwise, the first element in
source that
passes the test specified by predicate.
Remarks
Exceptions
| Exception | Condition |
|---|
| System..::.ArgumentNullException |
source or predicate is a null reference (Nothing in Visual Basic).
|
| System..::.AggregateException |
One or more exceptions occurred during the evaluation of the query.
|
| System..::.OperationCanceledException |
The query was canceled.
|
See Also
