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MongoQueryableFirstOrDefaultAsyncTSource Method (IMongoQueryableTSource, CancellationToken)

Returns the first element of a sequence, or a default value if the sequence contains no elements.

Namespace:  MongoDB.Driver.Linq
Assembly:  MongoDB.Driver (in MongoDB.Driver.dll) Version: 2.10.0+569905ff5e778c38ea19d9d0392496a83e1704ed
Syntax
public static Task<TSource> FirstOrDefaultAsync<TSource>(
	this IMongoQueryable<TSource> source,
	CancellationToken cancellationToken = null
)

Parameters

source
Type: MongoDB.Driver.LinqIMongoQueryableTSource
The IMongoQueryableT to return the first element of.
cancellationToken (Optional)
Type: System.ThreadingCancellationToken
The cancellation token.

Type Parameters

TSource
The type of the elements of source.

Return Value

Type: TaskTSource
default(TSource) if source is empty; otherwise, the first element in source.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IMongoQueryableTSource. 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).
See Also