ParallelEnumerable.DefaultIfEmpty Method

Definition

Returns the elements of the specified parallel sequence or the specified value in a singleton collection if the sequence is empty.

Overloads

DefaultIfEmpty<TSource>(ParallelQuery<TSource>)

Returns the elements of the specified parallel sequence or the type parameter's default value in a singleton collection if the sequence is empty.

DefaultIfEmpty<TSource>(ParallelQuery<TSource>, TSource)

Returns the elements of the specified parallel sequence or the specified value in a singleton collection if the sequence is empty.

DefaultIfEmpty<TSource>(ParallelQuery<TSource>)

Source:
ParallelEnumerable.cs
Source:
ParallelEnumerable.cs
Source:
ParallelEnumerable.cs

Returns the elements of the specified parallel sequence or the type parameter's default value in a singleton collection if the sequence is empty.

C#
public static System.Linq.ParallelQuery<TSource> DefaultIfEmpty<TSource>(this System.Linq.ParallelQuery<TSource> source);

Type Parameters

TSource

The type of the elements of source.

Parameters

source
ParallelQuery<TSource>

The sequence to return a default value for if it is empty.

Returns

A sequence that contains default(TSource) if source is empty; otherwise, source.

Exceptions

source is a null reference (Nothing in Visual Basic).

One or more exceptions occurred during the evaluation of the query.

See also

Applies to

.NET 9 and other versions
Product Versions
.NET Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 2.0, 2.1
UWP 10.0

DefaultIfEmpty<TSource>(ParallelQuery<TSource>, TSource)

Source:
ParallelEnumerable.cs
Source:
ParallelEnumerable.cs
Source:
ParallelEnumerable.cs

Returns the elements of the specified parallel sequence or the specified value in a singleton collection if the sequence is empty.

C#
public static System.Linq.ParallelQuery<TSource> DefaultIfEmpty<TSource>(this System.Linq.ParallelQuery<TSource> source, TSource defaultValue);

Type Parameters

TSource

The type of the elements of source.

Parameters

source
ParallelQuery<TSource>

The sequence to return the specified value for if it is empty.

defaultValue
TSource

The value to return if the sequence is empty.

Returns

A sequence that contains defaultValue if source is empty; otherwise, source.

Exceptions

source is a null reference (Nothing in Visual Basic).

One or more exceptions occurred during the evaluation of the query.

See also

Applies to

.NET 9 and other versions
Product Versions
.NET Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 2.0, 2.1
UWP 10.0