# ParallelEnumerable Class

**.NET Framework (current version)**

Provides a set of methods for querying objects that implement ParallelQuery{TSource}. This is the parallel equivalent of Enumerable.

**Namespace:**System.Linq

**Assembly:**System.Core (in System.Core.dll)

Name | Description | |
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Aggregate<TSource>(ParallelQuery<TSource>, Func<TSource, TSource, TSource>) | Applies in parallel an accumulator function over a sequence. | |

Aggregate<TSource, TAccumulate>(ParallelQuery<TSource>, TAccumulate, Func<TAccumulate, TSource, TAccumulate>) | Applies in parallel an accumulator function over a sequence. The specified seed value is used as the initial accumulator value. | |

Aggregate<TSource, TAccumulate, TResult>(ParallelQuery<TSource>, TAccumulate, Func<TAccumulate, TSource, TAccumulate>, Func<TAccumulate, TAccumulate, TAccumulate>, Func<TAccumulate, TResult>) | Applies in parallel an accumulator function over a sequence. This overload is not available in the sequential implementation. | |

Aggregate<TSource, TAccumulate, TResult>(ParallelQuery<TSource>, TAccumulate, Func<TAccumulate, TSource, TAccumulate>, Func<TAccumulate, TResult>) | Applies in parallel an accumulator function over a sequence. The specified seed value is used as the initial accumulator value, and the specified function is used to select the result value. | |

Aggregate<TSource, TAccumulate, TResult>(ParallelQuery<TSource>, Func<TAccumulate>, Func<TAccumulate, TSource, TAccumulate>, Func<TAccumulate, TAccumulate, TAccumulate>, Func<TAccumulate, TResult>) | Applies in parallel an accumulator function over a sequence. This overload is not available in the sequential implementation. | |

All<TSource>(ParallelQuery<TSource>, Func<TSource, Boolean>) | Determines in parallel whether all elements of a sequence satisfy a condition. | |

Any<TSource>(ParallelQuery<TSource>) | Determines whether a parallel sequence contains any elements. | |

Any<TSource>(ParallelQuery<TSource>, Func<TSource, Boolean>) | Determines in parallel whether any element of a sequence satisfies a condition. | |

AsEnumerable<TSource>(ParallelQuery<TSource>) | Converts a ParallelQuery<TSource> into an IEnumerable<T> to force sequential evaluation of the query. | |

AsOrdered(ParallelQuery) | Enables treatment of a data source as if it were ordered, overriding the default of unordered. AsOrdered may only be invoked on non-generic sequences returned by AsParallel, ParallelEnumerable.Range, and ParallelEnumerable.Repeat. | |

AsOrdered<TSource>(ParallelQuery<TSource>) | Enables treatment of a data source as if it were ordered, overriding the default of unordered. AsOrdered may only be invoked on generic sequences returned by AsParallel, ParallelEnumerable.Range, and ParallelEnumerable.Repeat. | |

AsParallel(IEnumerable) | Enables parallelization of a query. | |

AsParallel<TSource>(IEnumerable<TSource>) | Enables parallelization of a query. | |

AsParallel<TSource>(Partitioner<TSource>) | Enables parallelization of a query, as sourced by a custom partitioner that is responsible for splitting the input sequence into partitions. | |

AsSequential<TSource>(ParallelQuery<TSource>) | Converts a ParallelQuery<TSource> into an IEnumerable<T> to force sequential evaluation of the query. | |

AsUnordered<TSource>(ParallelQuery<TSource>) | Allows an intermediate query to be treated as if no ordering is implied among the elements. | |

Average(ParallelQuery<Decimal>) | Computes in parallel the average of a sequence of values. | |

Average(ParallelQuery<Double>) | Computes in parallel the average of a sequence of values. | |

Average(ParallelQuery<Int32>) | Computes in parallel the average of a sequence of values. | |

Average(ParallelQuery<Int64>) | Computes in parallel the average of a sequence of values. | |

Average(ParallelQuery<Nullable<Decimal>>) | Computes in parallel the average of a sequence of values. | |

Average(ParallelQuery<Nullable<Double>>) | Computes in parallel the average of a sequence of values. | |

Average(ParallelQuery<Nullable<Int32>>) | Computes in parallel the average of a sequence of values. | |

Average(ParallelQuery<Nullable<Int64>>) | Computes in parallel the average of a sequence of values. | |

Average(ParallelQuery<Nullable<Single>>) | Computes in parallel the average of a sequence of values. | |

Average(ParallelQuery<Single>) | Computes in parallel the average of a sequence of values. | |

Average<TSource>(ParallelQuery<TSource>, Func<TSource, Decimal>) | Computes in parallel the average of a sequence of values that are obtained by invoking a transform function on each element of the input sequence. | |

Average<TSource>(ParallelQuery<TSource>, Func<TSource, Double>) | Computes in parallel the average of a sequence of values that are obtained by invoking a transform function on each element of the input sequence. | |

Average<TSource>(ParallelQuery<TSource>, Func<TSource, Int32>) | Computes in parallel the average of a sequence of values that are obtained by invoking a transform function on each element of the input sequence. | |

Average<TSource>(ParallelQuery<TSource>, Func<TSource, Int64>) | ||

Average<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Decimal>>) | ||

Average<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Double>>) | ||

Average<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Int32>>) | ||

Average<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Int64>>) | ||

Average<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Single>>) | ||

Average<TSource>(ParallelQuery<TSource>, Func<TSource, Single>) | ||

Cast<TResult>(ParallelQuery) | Converts the elements of a ParallelQuery to the specified type. | |

Concat<TSource>(ParallelQuery<TSource>, IEnumerable<TSource>) |
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Concat<TSource>(ParallelQuery<TSource>, ParallelQuery<TSource>) | Concatenates two parallel sequences. | |

Contains<TSource>(ParallelQuery<TSource>, TSource) | Determines in parallel whether a sequence contains a specified element by using the default equality comparer. | |

Contains<TSource>(ParallelQuery<TSource>, TSource, IEqualityComparer<TSource>) | Determines in parallel whether a sequence contains a specified element by using a specified IEqualityComparer<T>. | |

Count<TSource>(ParallelQuery<TSource>) | Returns the number of elements in a parallel sequence. | |

Count<TSource>(ParallelQuery<TSource>, Func<TSource, Boolean>) | Returns a number that represents how many elements in the specified parallel sequence satisfy a condition. | |

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. | |

Distinct<TSource>(ParallelQuery<TSource>) | Returns distinct elements from a parallel sequence by using the default equality comparer to compare values. | |

Distinct<TSource>(ParallelQuery<TSource>, IEqualityComparer<TSource>) | Returns distinct elements from a parallel sequence by using a specified IEqualityComparer<T> to compare values. | |

ElementAt<TSource>(ParallelQuery<TSource>, Int32) | Returns the element at a specified index in a parallel sequence. | |

ElementAtOrDefault<TSource>(ParallelQuery<TSource>, Int32) | Returns the element at a specified index in a parallel sequence or a default value if the index is out of range. | |

Empty<TResult>() | Returns an empty ParallelQuery{TResult} that has the specified type argument. | |

Except<TSource>(ParallelQuery<TSource>, IEnumerable<TSource>) |
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Except<TSource>(ParallelQuery<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>) |
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Except<TSource>(ParallelQuery<TSource>, ParallelQuery<TSource>) | Produces the set difference of two parallel sequences by using the default equality comparer to compare values. | |

Except<TSource>(ParallelQuery<TSource>, ParallelQuery<TSource>, IEqualityComparer<TSource>) | Produces the set difference of two parallel sequences by using the specified IEqualityComparer<T> to compare values. | |

First<TSource>(ParallelQuery<TSource>) | Returns the first element of a parallel sequence. | |

First<TSource>(ParallelQuery<TSource>, Func<TSource, Boolean>) | Returns the first element in a parallel sequence that satisfies a specified condition. | |

FirstOrDefault<TSource>(ParallelQuery<TSource>) | Returns the first element of a parallel sequence, or a default value if the sequence contains no elements. | |

FirstOrDefault<TSource>(ParallelQuery<TSource>, Func<TSource, Boolean>) | Returns the first element of the parallel sequence that satisfies a condition or a default value if no such element is found. | |

ForAll<TSource>(ParallelQuery<TSource>, Action<TSource>) | Invokes in parallel the specified action for each element in the | |

GroupBy<TSource, TKey>(ParallelQuery<TSource>, Func<TSource, TKey>) | Groups in parallel the elements of a sequence according to a specified key selector function. | |

GroupBy<TSource, TKey>(ParallelQuery<TSource>, Func<TSource, TKey>, IEqualityComparer<TKey>) | Groups in parallel the elements of a sequence according to a specified key selector function and compares the keys by using a specified IComparer<T>. | |

GroupBy<TSource, TKey, TElement>(ParallelQuery<TSource>, Func<TSource, TKey>, Func<TSource, TElement>) | Groups in parallel the elements of a sequence according to a specified key selector function and projects the elements for each group by using a specified function. | |

GroupBy<TSource, TKey, TElement>(ParallelQuery<TSource>, Func<TSource, TKey>, Func<TSource, TElement>, IEqualityComparer<TKey>) | Groups in parallel the elements of a sequence according to a key selector function. The keys are compared by using a comparer and each group's elements are projected by using a specified function. | |

GroupBy<TSource, TKey, TResult>(ParallelQuery<TSource>, Func<TSource, TKey>, Func<TKey, IEnumerable<TSource>, TResult>) | Groups in parallel the elements of a sequence according to a specified key selector function and creates a result value from each group and its key. | |

GroupBy<TSource, TKey, TResult>(ParallelQuery<TSource>, Func<TSource, TKey>, Func<TKey, IEnumerable<TSource>, TResult>, IEqualityComparer<TKey>) | Groups in parallel the elements of a sequence according to a specified key selector function and creates a result value from each group and its key. The keys are compared by using a specified comparer. | |

GroupBy<TSource, TKey, TElement, TResult>(ParallelQuery<TSource>, Func<TSource, TKey>, Func<TSource, TElement>, Func<TKey, IEnumerable<TElement>, TResult>) | Groups in parallel the elements of a sequence according to a specified key selector function and creates a result value from each group and its key. The elements of each group are projected by using a specified function. | |

GroupBy<TSource, TKey, TElement, TResult>(ParallelQuery<TSource>, Func<TSource, TKey>, Func<TSource, TElement>, Func<TKey, IEnumerable<TElement>, TResult>, IEqualityComparer<TKey>) | Groups the elements of a sequence according to a specified key selector function and creates a result value from each group and its key. Key values are compared by using a specified comparer, and the elements of each group are projected by using a specified function. | |

GroupJoin<TOuter, TInner, TKey, TResult>(ParallelQuery<TOuter>, IEnumerable<TInner>, Func<TOuter, TKey>, Func<TInner, TKey>, Func<TOuter, IEnumerable<TInner>, TResult>) |
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GroupJoin<TOuter, TInner, TKey, TResult>(ParallelQuery<TOuter>, IEnumerable<TInner>, Func<TOuter, TKey>, Func<TInner, TKey>, Func<TOuter, IEnumerable<TInner>, TResult>, IEqualityComparer<TKey>) |
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GroupJoin<TOuter, TInner, TKey, TResult>(ParallelQuery<TOuter>, ParallelQuery<TInner>, Func<TOuter, TKey>, Func<TInner, TKey>, Func<TOuter, IEnumerable<TInner>, TResult>) | Correlates in parallel the elements of two sequences based on equality of keys and groups the results. The default equality comparer is used to compare keys. | |

GroupJoin<TOuter, TInner, TKey, TResult>(ParallelQuery<TOuter>, ParallelQuery<TInner>, Func<TOuter, TKey>, Func<TInner, TKey>, Func<TOuter, IEnumerable<TInner>, TResult>, IEqualityComparer<TKey>) | Correlates in parallel the elements of two sequences based on key equality and groups the results. A specified IEqualityComparer<T> is used to compare keys. | |

Intersect<TSource>(ParallelQuery<TSource>, IEnumerable<TSource>) |
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Intersect<TSource>(ParallelQuery<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>) |
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Intersect<TSource>(ParallelQuery<TSource>, ParallelQuery<TSource>) | Produces the set intersection of two parallel sequences by using the default equality comparer to compare values. | |

Intersect<TSource>(ParallelQuery<TSource>, ParallelQuery<TSource>, IEqualityComparer<TSource>) | Produces the set intersection of two parallel sequences by using the specified IEqualityComparer{T} to compare values. | |

Join<TOuter, TInner, TKey, TResult>(ParallelQuery<TOuter>, IEnumerable<TInner>, Func<TOuter, TKey>, Func<TInner, TKey>, Func<TOuter, TInner, TResult>) |
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Join<TOuter, TInner, TKey, TResult>(ParallelQuery<TOuter>, IEnumerable<TInner>, Func<TOuter, TKey>, Func<TInner, TKey>, Func<TOuter, TInner, TResult>, IEqualityComparer<TKey>) |
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Join<TOuter, TInner, TKey, TResult>(ParallelQuery<TOuter>, ParallelQuery<TInner>, Func<TOuter, TKey>, Func<TInner, TKey>, Func<TOuter, TInner, TResult>) | Correlates in parallel the elements of two sequences based on matching keys. The default equality comparer is used to compare keys. | |

Join<TOuter, TInner, TKey, TResult>(ParallelQuery<TOuter>, ParallelQuery<TInner>, Func<TOuter, TKey>, Func<TInner, TKey>, Func<TOuter, TInner, TResult>, IEqualityComparer<TKey>) | Correlates in parallel the elements of two sequences based on matching keys. A specified IEqualityComparer<T> is used to compare keys. | |

Last<TSource>(ParallelQuery<TSource>) | Returns the last element of a parallel sequence. | |

Last<TSource>(ParallelQuery<TSource>, Func<TSource, Boolean>) | Returns the last element of a parallel sequence that satisfies a specified condition. | |

LastOrDefault<TSource>(ParallelQuery<TSource>) | Returns the last element of a parallel sequence, or a default value if the sequence contains no elements. | |

LastOrDefault<TSource>(ParallelQuery<TSource>, Func<TSource, Boolean>) | Returns the last element of a parallel sequence that satisfies a condition, or a default value if no such element is found. | |

LongCount<TSource>(ParallelQuery<TSource>) | Returns an Int64 that represents the total number of elements in a parallel sequence. | |

LongCount<TSource>(ParallelQuery<TSource>, Func<TSource, Boolean>) | Returns an Int64 that represents how many elements in a parallel sequence satisfy a condition. | |

Max(ParallelQuery<Decimal>) | Returns the maximum value in a parallel sequence of values. | |

Max(ParallelQuery<Double>) | Returns the maximum value in a parallel sequence of values. | |

Max(ParallelQuery<Int32>) | Returns the maximum value in a parallel sequence of values. | |

Max(ParallelQuery<Int64>) | Returns the maximum value in a parallel sequence of values. | |

Max(ParallelQuery<Nullable<Decimal>>) | Returns the maximum value in a parallel sequence of values. | |

Max(ParallelQuery<Nullable<Double>>) | Returns the maximum value in a parallel sequence of values. | |

Max(ParallelQuery<Nullable<Int32>>) | Returns the maximum value in a parallel sequence of values. | |

Max(ParallelQuery<Nullable<Int64>>) | Returns the maximum value in a parallel sequence of values. | |

Max(ParallelQuery<Nullable<Single>>) | Returns the maximum value in a parallel sequence of values. | |

Max(ParallelQuery<Single>) | Returns the maximum value in a parallel sequence of values. | |

Max<TSource>(ParallelQuery<TSource>) | Returns the maximum value in a parallel sequence of values. | |

Max<TSource>(ParallelQuery<TSource>, Func<TSource, Decimal>) | Invokes in parallel a transform function on each element of a sequence and returns the maximum value. | |

Max<TSource>(ParallelQuery<TSource>, Func<TSource, Double>) | Invokes in parallel a transform function on each element of a sequence and returns the maximum value. | |

Max<TSource>(ParallelQuery<TSource>, Func<TSource, Int32>) | Invokes in parallel a transform function on each element of a sequence and returns the maximum value. | |

Max<TSource>(ParallelQuery<TSource>, Func<TSource, Int64>) | ||

Max<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Decimal>>) | ||

Max<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Double>>) | ||

Max<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Int32>>) | ||

Max<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Int64>>) | ||

Max<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Single>>) | ||

Max<TSource>(ParallelQuery<TSource>, Func<TSource, Single>) | ||

Max<TSource, TResult>(ParallelQuery<TSource>, Func<TSource, TResult>) | ||

Min(ParallelQuery<Decimal>) | Returns the minimum value in a parallel sequence of values. | |

Min(ParallelQuery<Double>) | Returns the minimum value in a parallel sequence of values. | |

Min(ParallelQuery<Int32>) | Returns the minimum value in a parallel sequence of values. | |

Min(ParallelQuery<Int64>) | Returns the minimum value in a parallel sequence of values. | |

Min(ParallelQuery<Nullable<Decimal>>) | Returns the minimum value in a parallel sequence of values. | |

Min(ParallelQuery<Nullable<Double>>) | Returns the minimum value in a parallel sequence of values. | |

Min(ParallelQuery<Nullable<Int32>>) | Returns the minimum value in a parallel sequence of values. | |

Min(ParallelQuery<Nullable<Int64>>) | Returns the minimum value in a parallel sequence of values. | |

Min(ParallelQuery<Nullable<Single>>) | Returns the minimum value in a parallel sequence of values. | |

Min(ParallelQuery<Single>) | Returns the minimum value in a parallel sequence of values. | |

Min<TSource>(ParallelQuery<TSource>) | Returns the minimum value in a parallel sequence of values. | |

Min<TSource>(ParallelQuery<TSource>, Func<TSource, Decimal>) | Invokes in parallel a transform function on each element of a sequence and returns the minimum value. | |

Min<TSource>(ParallelQuery<TSource>, Func<TSource, Double>) | Invokes in parallel a transform function on each element of a sequence and returns the minimum value. | |

Min<TSource>(ParallelQuery<TSource>, Func<TSource, Int32>) | Invokes in parallel a transform function on each element of a sequence and returns the minimum value. | |

Min<TSource>(ParallelQuery<TSource>, Func<TSource, Int64>) | ||

Min<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Decimal>>) | ||

Min<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Double>>) | ||

Min<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Int32>>) | ||

Min<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Int64>>) | ||

Min<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Single>>) | ||

Min<TSource>(ParallelQuery<TSource>, Func<TSource, Single>) | ||

Min<TSource, TResult>(ParallelQuery<TSource>, Func<TSource, TResult>) | ||

OfType<TResult>(ParallelQuery) | Filters the elements of a ParallelQuery based on a specified type. | |

OrderBy<TSource, TKey>(ParallelQuery<TSource>, Func<TSource, TKey>) | Sorts in parallel the elements of a sequence in ascending order according to a key. | |

OrderBy<TSource, TKey>(ParallelQuery<TSource>, Func<TSource, TKey>, IComparer<TKey>) | Sorts in parallel the elements of a sequence in ascending order by using a specified comparer. | |

OrderByDescending<TSource, TKey>(ParallelQuery<TSource>, Func<TSource, TKey>) | Sorts in parallel the elements of a sequence in descending order according to a key. | |

OrderByDescending<TSource, TKey>(ParallelQuery<TSource>, Func<TSource, TKey>, IComparer<TKey>) | Sorts the elements of a sequence in descending order by using a specified comparer. | |

Range(Int32, Int32) | Generates a parallel sequence of integral numbers within a specified range. | |

Repeat<TResult>(TResult, Int32) | Generates a parallel sequence that contains one repeated value. | |

Reverse<TSource>(ParallelQuery<TSource>) | Inverts the order of the elements in a parallel sequence. | |

Select<TSource, TResult>(ParallelQuery<TSource>, Func<TSource, TResult>) | Projects in parallel each element of a sequence into a new form. | |

Select<TSource, TResult>(ParallelQuery<TSource>, Func<TSource, Int32, TResult>) | Projects in parallel each element of a sequence into a new form by incorporating the element's index. | |

SelectMany<TSource, TResult>(ParallelQuery<TSource>, Func<TSource, IEnumerable<TResult>>) | Projects in parallel each element of a sequence to an IEnumerable<T> and flattens the resulting sequences into one sequence. | |

SelectMany<TSource, TResult>(ParallelQuery<TSource>, Func<TSource, Int32, IEnumerable<TResult>>) | Projects in parallel each element of a sequence to an IEnumerable<T>, and flattens the resulting sequences into one sequence. The index of each source element is used in the projected form of that element. | |

SelectMany<TSource, TCollection, TResult>(ParallelQuery<TSource>, Func<TSource, IEnumerable<TCollection>>, Func<TSource, TCollection, TResult>) | Projects each element of a sequence to an IEnumerable<T>, flattens the resulting sequences into one sequence, and invokes a result selector function on each element therein. | |

SelectMany<TSource, TCollection, TResult>(ParallelQuery<TSource>, Func<TSource, Int32, IEnumerable<TCollection>>, Func<TSource, TCollection, TResult>) | Projects each element of a sequence to an IEnumerable<T>, flattens the resulting sequences into one sequence, and invokes a result selector function on each element therein. The index of each source element is used in the intermediate projected form of that element. | |

SequenceEqual<TSource>(ParallelQuery<TSource>, IEnumerable<TSource>) |
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SequenceEqual<TSource>(ParallelQuery<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>) |
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SequenceEqual<TSource>(ParallelQuery<TSource>, ParallelQuery<TSource>) | Determines whether two parallel sequences are equal by comparing the elements by using the default equality comparer for their type. | |

SequenceEqual<TSource>(ParallelQuery<TSource>, ParallelQuery<TSource>, IEqualityComparer<TSource>) | Determines whether two parallel sequences are equal by comparing their elements by using a specified IEqualityComparer{T}. | |

Single<TSource>(ParallelQuery<TSource>) | Returns the only element of a parallel sequence, and throws an exception if there is not exactly one element in the sequence. | |

Single<TSource>(ParallelQuery<TSource>, Func<TSource, Boolean>) | Returns the only element of a parallel sequence that satisfies a specified condition, and throws an exception if more than one such element exists. | |

SingleOrDefault<TSource>(ParallelQuery<TSource>) | Returns the only element of a parallel sequence, or a default value if the sequence is empty; this method throws an exception if there is more than one element in the sequence. | |

SingleOrDefault<TSource>(ParallelQuery<TSource>, Func<TSource, Boolean>) | Returns the only element of a parallel sequence that satisfies a specified condition or a default value if no such element exists; this method throws an exception if more than one element satisfies the condition. | |

Skip<TSource>(ParallelQuery<TSource>, Int32) | Bypasses a specified number of elements in a parallel sequence and then returns the remaining elements. | |

SkipWhile<TSource>(ParallelQuery<TSource>, Func<TSource, Boolean>) | Bypasses elements in a parallel sequence as long as a specified condition is true and then returns the remaining elements. | |

SkipWhile<TSource>(ParallelQuery<TSource>, Func<TSource, Int32, Boolean>) | Bypasses elements in a parallel sequence as long as a specified condition is true and then returns the remaining elements. The element's index is used in the logic of the predicate function. | |

Sum(ParallelQuery<Decimal>) | Computes in parallel the sum of a sequence of values. | |

Sum(ParallelQuery<Double>) | Computes in parallel the sum of a sequence of values. | |

Sum(ParallelQuery<Int32>) | Computes in parallel the sum of a sequence of values. | |

Sum(ParallelQuery<Int64>) | Computes in parallel the sum of a sequence of values. | |

Sum(ParallelQuery<Nullable<Decimal>>) | Computes in parallel the sum of a sequence of values. | |

Sum(ParallelQuery<Nullable<Double>>) | Computes in parallel the sum of a sequence of values. | |

Sum(ParallelQuery<Nullable<Int32>>) | Computes in parallel the sum of a sequence of values. | |

Sum(ParallelQuery<Nullable<Int64>>) | Computes in parallel the sum of a sequence of values. | |

Sum(ParallelQuery<Nullable<Single>>) | Computes in parallel the sum of a sequence of values. | |

Sum(ParallelQuery<Single>) | Computes in parallel the sum of a sequence of values. | |

Sum<TSource>(ParallelQuery<TSource>, Func<TSource, Decimal>) | Computes in parallel the sum of the sequence of values that are obtained by invoking a transform function on each element of the input sequence. | |

Sum<TSource>(ParallelQuery<TSource>, Func<TSource, Double>) | Computes in parallel the sum of the sequence of values that are obtained by invoking a transform function on each element of the input sequence. | |

Sum<TSource>(ParallelQuery<TSource>, Func<TSource, Int32>) | Computes in parallel the sum of the sequence of values that are obtained by invoking a transform function on each element of the input sequence. | |

Sum<TSource>(ParallelQuery<TSource>, Func<TSource, Int64>) | ||

Sum<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Decimal>>) | ||

Sum<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Double>>) | ||

Sum<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Int32>>) | ||

Sum<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Int64>>) | ||

Sum<TSource>(ParallelQuery<TSource>, Func<TSource, Nullable<Single>>) | ||

Sum<TSource>(ParallelQuery<TSource>, Func<TSource, Single>) | ||

Take<TSource>(ParallelQuery<TSource>, Int32) | Returns a specified number of contiguous elements from the start of a parallel sequence. | |

TakeWhile<TSource>(ParallelQuery<TSource>, Func<TSource, Boolean>) | Returns elements from a parallel sequence as long as a specified condition is true. | |

TakeWhile<TSource>(ParallelQuery<TSource>, Func<TSource, Int32, Boolean>) | Returns elements from a parallel sequence as long as a specified condition is true. The element's index is used in the logic of the predicate function. | |

ThenBy<TSource, TKey>(OrderedParallelQuery<TSource>, Func<TSource, TKey>) | Performs in parallel a subsequent ordering of the elements in a sequence in ascending order according to a key. | |

ThenBy<TSource, TKey>(OrderedParallelQuery<TSource>, Func<TSource, TKey>, IComparer<TKey>) | Performs in parallel a subsequent ordering of the elements in a sequence in ascending order by using a specified comparer. | |

ThenByDescending<TSource, TKey>(OrderedParallelQuery<TSource>, Func<TSource, TKey>) | Performs in parallel a subsequent ordering of the elements in a sequence in descending order, according to a key. | |

ThenByDescending<TSource, TKey>(OrderedParallelQuery<TSource>, Func<TSource, TKey>, IComparer<TKey>) | Performs in parallel a subsequent ordering of the elements in a sequence in descending order by using a specified comparer. | |

ToArray<TSource>(ParallelQuery<TSource>) | Creates an array from a ParallelQuery<TSource>. | |

ToDictionary<TSource, TKey>(ParallelQuery<TSource>, Func<TSource, TKey>) | Creates a Dictionary<TKey, TValue> from a ParallelQuery<TSource> according to a specified key selector function. | |

ToDictionary<TSource, TKey>(ParallelQuery<TSource>, Func<TSource, TKey>, IEqualityComparer<TKey>) | Creates a Dictionary<TKey, TValue> from a ParallelQuery<TSource> according to a specified key selector function and key comparer. | |

ToDictionary<TSource, TKey, TElement>(ParallelQuery<TSource>, Func<TSource, TKey>, Func<TSource, TElement>) | Creates a Dictionary<TKey, TValue> from a ParallelQuery<TSource> according to specified key selector and element selector functions. | |

ToDictionary<TSource, TKey, TElement>(ParallelQuery<TSource>, Func<TSource, TKey>, Func<TSource, TElement>, IEqualityComparer<TKey>) | Creates a Dictionary<TKey, TValue> from a ParallelQuery<TSource> according to a specified key selector function, a comparer, and an element selector function. | |

ToList<TSource>(ParallelQuery<TSource>) | Creates a List<T> from an ParallelQuery<TSource>. | |

ToLookup<TSource, TKey>(ParallelQuery<TSource>, Func<TSource, TKey>) | Creates an ILookup<TKey, TElement> from a ParallelQuery<TSource> according to a specified key selector function. | |

ToLookup<TSource, TKey>(ParallelQuery<TSource>, Func<TSource, TKey>, IEqualityComparer<TKey>) | Creates an ILookup<TKey, TElement> from a ParallelQuery<TSource> according to a specified key selector function and key comparer. | |

ToLookup<TSource, TKey, TElement>(ParallelQuery<TSource>, Func<TSource, TKey>, Func<TSource, TElement>) | Creates an ILookup<TKey, TElement> from a ParallelQuery<TSource> according to specified key selector and element selector functions. | |

ToLookup<TSource, TKey, TElement>(ParallelQuery<TSource>, Func<TSource, TKey>, Func<TSource, TElement>, IEqualityComparer<TKey>) | Creates an ILookup<TKey, TElement> from a ParallelQuery<TSource> according to a specified key selector function, a comparer and an element selector function. | |

Union<TSource>(ParallelQuery<TSource>, IEnumerable<TSource>) |
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Union<TSource>(ParallelQuery<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>) |
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Union<TSource>(ParallelQuery<TSource>, ParallelQuery<TSource>) | Produces the set union of two parallel sequences by using the default equality comparer. | |

Union<TSource>(ParallelQuery<TSource>, ParallelQuery<TSource>, IEqualityComparer<TSource>) | Produces the set union of two parallel sequences by using a specified IEqualityComparer{T}. | |

Where<TSource>(ParallelQuery<TSource>, Func<TSource, Boolean>) | Filters in parallel a sequence of values based on a predicate. | |

Where<TSource>(ParallelQuery<TSource>, Func<TSource, Int32, Boolean>) | Filters in parallel a sequence of values based on a predicate. Each element's index is used in the logic of the predicate function. | |

WithCancellation<TSource>(ParallelQuery<TSource>, CancellationToken) | Sets the CancellationToken to associate with the query. | |

WithDegreeOfParallelism<TSource>(ParallelQuery<TSource>, Int32) | Sets the degree of parallelism to use in a query. Degree of parallelism is the maximum number of concurrently executing tasks that will be used to process the query. | |

WithExecutionMode<TSource>(ParallelQuery<TSource>, ParallelExecutionMode) | Sets the execution mode of the query. | |

WithMergeOptions<TSource>(ParallelQuery<TSource>, ParallelMergeOptions) | Sets the merge options for this query, which specify how the query will buffer output. | |

Zip<TFirst, TSecond, TResult>(ParallelQuery<TFirst>, IEnumerable<TSecond>, Func<TFirst, TSecond, TResult>) |
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Zip<TFirst, TSecond, TResult>(ParallelQuery<TFirst>, ParallelQuery<TSecond>, Func<TFirst, TSecond, TResult>) | Merges in parallel two sequences by using the specified predicate function. |

**Universal Windows Platform**

Available since 8

**.NET Framework**

Available since 4.0

**Portable Class Library**

Supported in: portable .NET platforms

**Windows Phone**

Available since 8.1

Any public static (
**Shared**
in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.