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HashSet<T> Class

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Represents a set of values.

Inheritance Hierarchy

System.Object
  System.Collections.Generic.HashSet<T>

Namespace:  System.Collections.Generic
Assembly:  System.Core (in System.Core.dll)

Syntax

'Declaration
<DebuggerDisplayAttribute("Count = {Count}")> _
Public Class HashSet(Of T) _
    Implements ISet(Of T), ICollection(Of T),  _
    IEnumerable(Of T), IEnumerable

[DebuggerDisplayAttribute("Count = {Count}")]
public class HashSet<T> : ISet<T>, ICollection<T>, 
    IEnumerable<T>, IEnumerable

Type Parameters

  • T
    The type of elements in the hash set.

The HashSet<T> type exposes the following members.

Constructors

  Name Description
Public method HashSet<T>() Initializes a new instance of the HashSet<T> class that is empty and uses the default equality comparer for the set type.
Public method HashSet<T>(IEnumerable<T>) Initializes a new instance of the HashSet<T> class that uses the default equality comparer for the set type, contains elements copied from the specified collection, and has sufficient capacity to accommodate the number of elements copied.
Public method HashSet<T>(IEqualityComparer<T>) Initializes a new instance of the HashSet<T> class that is empty and uses the specified equality comparer for the set type.
Public method HashSet<T>(IEnumerable<T>, IEqualityComparer<T>) Initializes a new instance of the HashSet<T> class that uses the specified equality comparer for the set type, contains elements copied from the specified collection, and has sufficient capacity to accommodate the number of elements copied.

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Properties

  Name Description
Public property Comparer Gets the IEqualityComparer<T> object that is used to determine equality for the values in the set.
Public property Count Gets the number of elements that are contained in a set.

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Methods

  Name Description
Public method Add Adds the specified element to a set.
Public method Clear Removes all elements from a HashSet<T> object.
Public method Contains Determines whether a HashSet<T> object contains the specified element.
Public method CopyTo(array<T[]) Copies the elements of a HashSet<T> object to an array.
Public method CopyTo(array<T[], Int32) Copies the elements of a HashSet<T> object to an array, starting at the specified array index.
Public method CopyTo(array<T[], Int32, Int32) Copies the specified number of elements of a HashSet<T> object to an array, starting at the specified array index.
Public method Equals(Object) Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Public method ExceptWith Removes all elements in the specified collection from the current HashSet<T> object.
Protected method Finalize Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
Public method GetEnumerator Returns an enumerator that iterates through a HashSet<T> object.
Public method GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
Public method GetType Gets the Type of the current instance. (Inherited from Object.)
Public method IntersectWith Modifies the current HashSet<T> object to contain only elements that are present in that object and in the specified collection.
Public method IsProperSubsetOf Determines whether a HashSet<T> object is a proper subset of the specified collection.
Public method IsProperSupersetOf Determines whether a HashSet<T> object is a proper superset of the specified collection.
Public method IsSubsetOf Determines whether a HashSet<T> object is a subset of the specified collection.
Public method IsSupersetOf Determines whether a HashSet<T> object is a superset of the specified collection.
Protected method MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Public method Overlaps Determines whether the current HashSet<T> object and a specified collection share common elements.
Public method Remove Removes the specified element from a HashSet<T> object.
Public method RemoveWhere Removes all elements that match the conditions defined by the specified predicate from a HashSet<T> collection.
Public method SetEquals Determines whether a HashSet<T> object and the specified collection contain the same elements.
Public method SymmetricExceptWith Modifies the current HashSet<T> object to contain only elements that are present either in that object or in the specified collection, but not both.
Public method ToString Returns a string that represents the current object. (Inherited from Object.)
Public method TrimExcess Sets the capacity of a HashSet<T> object to the actual number of elements it contains, rounded up to a nearby, implementation-specific value.
Public method UnionWith Modifies the current HashSet<T> object to contain all elements that are present in both itself and in the specified collection.

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Extension Methods

  Name Description
Public Extension Method Aggregate<T>(Func<T, T, T>) Overloaded. Applies an accumulator function over a sequence. (Defined by Enumerable.)
Public Extension Method Aggregate<T, TAccumulate>(TAccumulate, Func<TAccumulate, T, TAccumulate>) Overloaded. Applies an accumulator function over a sequence. The specified seed value is used as the initial accumulator value. (Defined by Enumerable.)
Public Extension Method Aggregate<T, TAccumulate, TResult>(TAccumulate, Func<TAccumulate, T, TAccumulate>, Func<TAccumulate, TResult>) Overloaded. Applies 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. (Defined by Enumerable.)
Public Extension Method All<T> Determines whether all elements of a sequence satisfy a condition. (Defined by Enumerable.)
Public Extension Method Any<T>() Overloaded. Determines whether a sequence contains any elements. (Defined by Enumerable.)
Public Extension Method Any<T>(Func<T, Boolean>) Overloaded. Determines whether any element of a sequence satisfies a condition. (Defined by Enumerable.)
Public Extension Method AsEnumerable<T> Returns the input typed as IEnumerable<T>. (Defined by Enumerable.)
Public Extension Method AsQueryable() Overloaded. Converts an IEnumerable to an IQueryable. (Defined by Queryable.)
Public Extension Method AsQueryable<T>() Overloaded. Converts a generic IEnumerable<T> to a generic IQueryable<T>. (Defined by Queryable.)
Public Extension Method Average<T>(Func<T, Decimal>) Overloaded. Computes the average of a sequence of Decimal values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Average<T>(Func<T, Nullable<Decimal>>) Overloaded. Computes the average of a sequence of nullable Decimal values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Average<T>(Func<T, Double>) Overloaded. Computes the average of a sequence of Double values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Average<T>(Func<T, Nullable<Double>>) Overloaded. Computes the average of a sequence of nullable Double values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Average<T>(Func<T, Int32>) Overloaded. Computes the average of a sequence of Int32 values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Average<T>(Func<T, Nullable<Int32>>) Overloaded. Computes the average of a sequence of nullable Int32 values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Average<T>(Func<T, Int64>) Overloaded. Computes the average of a sequence of Int64 values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Average<T>(Func<T, Nullable<Int64>>) Overloaded. Computes the average of a sequence of nullable Int64 values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Average<T>(Func<T, Single>) Overloaded. Computes the average of a sequence of Single values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Average<T>(Func<T, Nullable<Single>>) Overloaded. Computes the average of a sequence of nullable Single values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Cast<TResult> Converts the elements of an IEnumerable to the specified type. (Defined by Enumerable.)
Public Extension Method Concat<T> Concatenates two sequences. (Defined by Enumerable.)
Public Extension Method Contains<T>(T) Overloaded. Determines whether a sequence contains a specified element by using the default equality comparer. (Defined by Enumerable.)
Public Extension Method Contains<T>(T, IEqualityComparer<T>) Overloaded. Determines whether a sequence contains a specified element by using a specified IEqualityComparer<T>. (Defined by Enumerable.)
Public Extension Method Count<T>() Overloaded. Returns the number of elements in a sequence. (Defined by Enumerable.)
Public Extension Method Count<T>(Func<T, Boolean>) Overloaded. Returns a number that represents how many elements in the specified sequence satisfy a condition. (Defined by Enumerable.)
Public Extension Method DefaultIfEmpty<T>() Overloaded. Returns the elements of the specified sequence or the type parameter's default value in a singleton collection if the sequence is empty. (Defined by Enumerable.)
Public Extension Method DefaultIfEmpty<T>(T) Overloaded. Returns the elements of the specified sequence or the specified value in a singleton collection if the sequence is empty. (Defined by Enumerable.)
Public Extension Method Distinct<T>() Overloaded. Returns distinct elements from a sequence by using the default equality comparer to compare values. (Defined by Enumerable.)
Public Extension Method Distinct<T>(IEqualityComparer<T>) Overloaded. Returns distinct elements from a sequence by using a specified IEqualityComparer<T> to compare values. (Defined by Enumerable.)
Public Extension Method ElementAt<T> Returns the element at a specified index in a sequence. (Defined by Enumerable.)
Public Extension Method ElementAtOrDefault<T> Returns the element at a specified index in a sequence or a default value if the index is out of range. (Defined by Enumerable.)
Public Extension Method Except<T>(IEnumerable<T>) Overloaded. Produces the set difference of two sequences by using the default equality comparer to compare values. (Defined by Enumerable.)
Public Extension Method Except<T>(IEnumerable<T>, IEqualityComparer<T>) Overloaded. Produces the set difference of two sequences by using the specified IEqualityComparer<T> to compare values. (Defined by Enumerable.)
Public Extension Method First<T>() Overloaded. Returns the first element of a sequence. (Defined by Enumerable.)
Public Extension Method First<T>(Func<T, Boolean>) Overloaded. Returns the first element in a sequence that satisfies a specified condition. (Defined by Enumerable.)
Public Extension Method FirstOrDefault<T>() Overloaded. Returns the first element of a sequence, or a default value if the sequence contains no elements. (Defined by Enumerable.)
Public Extension Method FirstOrDefault<T>(Func<T, Boolean>) Overloaded. Returns the first element of the sequence that satisfies a condition or a default value if no such element is found. (Defined by Enumerable.)
Public Extension Method GroupBy<T, TKey>(Func<T, TKey>) Overloaded. Groups the elements of a sequence according to a specified key selector function. (Defined by Enumerable.)
Public Extension Method GroupBy<T, TKey>(Func<T, TKey>, IEqualityComparer<TKey>) Overloaded. Groups the elements of a sequence according to a specified key selector function and compares the keys by using a specified comparer. (Defined by Enumerable.)
Public Extension Method GroupBy<T, TKey, TElement>(Func<T, TKey>, Func<T, TElement>) Overloaded. Groups the elements of a sequence according to a specified key selector function and projects the elements for each group by using a specified function. (Defined by Enumerable.)
Public Extension Method GroupBy<T, TKey, TResult>(Func<T, TKey>, Func<TKey, IEnumerable<T>, TResult>) Overloaded. Groups the elements of a sequence according to a specified key selector function and creates a result value from each group and its key. (Defined by Enumerable.)
Public Extension Method GroupBy<T, TKey, TElement>(Func<T, TKey>, Func<T, TElement>, IEqualityComparer<TKey>) Overloaded. Groups 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. (Defined by Enumerable.)
Public Extension Method GroupBy<T, TKey, TResult>(Func<T, TKey>, Func<TKey, IEnumerable<T>, TResult>, IEqualityComparer<TKey>) Overloaded. Groups 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. (Defined by Enumerable.)
Public Extension Method GroupBy<T, TKey, TElement, TResult>(Func<T, TKey>, Func<T, TElement>, Func<TKey, IEnumerable<TElement>, TResult>) Overloaded. Groups 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. (Defined by Enumerable.)
Public Extension Method GroupBy<T, TKey, TElement, TResult>(Func<T, TKey>, Func<T, TElement>, Func<TKey, IEnumerable<TElement>, TResult>, IEqualityComparer<TKey>) Overloaded. 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. (Defined by Enumerable.)
Public Extension Method GroupJoin<T, TInner, TKey, TResult>(IEnumerable<TInner>, Func<T, TKey>, Func<TInner, TKey>, Func<T, IEnumerable<TInner>, TResult>) Overloaded. Correlates the elements of two sequences based on equality of keys and groups the results. The default equality comparer is used to compare keys. (Defined by Enumerable.)
Public Extension Method GroupJoin<T, TInner, TKey, TResult>(IEnumerable<TInner>, Func<T, TKey>, Func<TInner, TKey>, Func<T, IEnumerable<TInner>, TResult>, IEqualityComparer<TKey>) Overloaded. Correlates the elements of two sequences based on key equality and groups the results. A specified IEqualityComparer<T> is used to compare keys. (Defined by Enumerable.)
Public Extension Method Intersect<T>(IEnumerable<T>) Overloaded. Produces the set intersection of two sequences by using the default equality comparer to compare values. (Defined by Enumerable.)
Public Extension Method Intersect<T>(IEnumerable<T>, IEqualityComparer<T>) Overloaded. Produces the set intersection of two sequences by using the specified IEqualityComparer<T> to compare values. (Defined by Enumerable.)
Public Extension Method Join<T, TInner, TKey, TResult>(IEnumerable<TInner>, Func<T, TKey>, Func<TInner, TKey>, Func<T, TInner, TResult>) Overloaded. Correlates the elements of two sequences based on matching keys. The default equality comparer is used to compare keys. (Defined by Enumerable.)
Public Extension Method Join<T, TInner, TKey, TResult>(IEnumerable<TInner>, Func<T, TKey>, Func<TInner, TKey>, Func<T, TInner, TResult>, IEqualityComparer<TKey>) Overloaded. Correlates the elements of two sequences based on matching keys. A specified IEqualityComparer<T> is used to compare keys. (Defined by Enumerable.)
Public Extension Method Last<T>() Overloaded. Returns the last element of a sequence. (Defined by Enumerable.)
Public Extension Method Last<T>(Func<T, Boolean>) Overloaded. Returns the last element of a sequence that satisfies a specified condition. (Defined by Enumerable.)
Public Extension Method LastOrDefault<T>() Overloaded. Returns the last element of a sequence, or a default value if the sequence contains no elements. (Defined by Enumerable.)
Public Extension Method LastOrDefault<T>(Func<T, Boolean>) Overloaded. Returns the last element of a sequence that satisfies a condition or a default value if no such element is found. (Defined by Enumerable.)
Public Extension Method LongCount<T>() Overloaded. Returns an Int64 that represents the total number of elements in a sequence. (Defined by Enumerable.)
Public Extension Method LongCount<T>(Func<T, Boolean>) Overloaded. Returns an Int64 that represents how many elements in a sequence satisfy a condition. (Defined by Enumerable.)
Public Extension Method Max<T>() Overloaded. Returns the maximum value in a generic sequence. (Defined by Enumerable.)
Public Extension Method Max<T>(Func<T, Decimal>) Overloaded. Invokes a transform function on each element of a sequence and returns the maximum Decimal value. (Defined by Enumerable.)
Public Extension Method Max<T>(Func<T, Nullable<Decimal>>) Overloaded. Invokes a transform function on each element of a sequence and returns the maximum nullable Decimal value. (Defined by Enumerable.)
Public Extension Method Max<T>(Func<T, Double>) Overloaded. Invokes a transform function on each element of a sequence and returns the maximum Double value. (Defined by Enumerable.)
Public Extension Method Max<T>(Func<T, Nullable<Double>>) Overloaded. Invokes a transform function on each element of a sequence and returns the maximum nullable Double value. (Defined by Enumerable.)
Public Extension Method Max<T>(Func<T, Int32>) Overloaded. Invokes a transform function on each element of a sequence and returns the maximum Int32 value. (Defined by Enumerable.)
Public Extension Method Max<T>(Func<T, Nullable<Int32>>) Overloaded. Invokes a transform function on each element of a sequence and returns the maximum nullable Int32 value. (Defined by Enumerable.)
Public Extension Method Max<T>(Func<T, Int64>) Overloaded. Invokes a transform function on each element of a sequence and returns the maximum Int64 value. (Defined by Enumerable.)
Public Extension Method Max<T>(Func<T, Nullable<Int64>>) Overloaded. Invokes a transform function on each element of a sequence and returns the maximum nullable Int64 value. (Defined by Enumerable.)
Public Extension Method Max<T>(Func<T, Single>) Overloaded. Invokes a transform function on each element of a sequence and returns the maximum Single value. (Defined by Enumerable.)
Public Extension Method Max<T>(Func<T, Nullable<Single>>) Overloaded. Invokes a transform function on each element of a sequence and returns the maximum nullable Single value. (Defined by Enumerable.)
Public Extension Method Max<T, TResult>(Func<T, TResult>) Overloaded. Invokes a transform function on each element of a generic sequence and returns the maximum resulting value. (Defined by Enumerable.)
Public Extension Method Min<T>() Overloaded. Returns the minimum value in a generic sequence. (Defined by Enumerable.)
Public Extension Method Min<T>(Func<T, Decimal>) Overloaded. Invokes a transform function on each element of a sequence and returns the minimum Decimal value. (Defined by Enumerable.)
Public Extension Method Min<T>(Func<T, Nullable<Decimal>>) Overloaded. Invokes a transform function on each element of a sequence and returns the minimum nullable Decimal value. (Defined by Enumerable.)
Public Extension Method Min<T>(Func<T, Double>) Overloaded. Invokes a transform function on each element of a sequence and returns the minimum Double value. (Defined by Enumerable.)
Public Extension Method Min<T>(Func<T, Nullable<Double>>) Overloaded. Invokes a transform function on each element of a sequence and returns the minimum nullable Double value. (Defined by Enumerable.)
Public Extension Method Min<T>(Func<T, Int32>) Overloaded. Invokes a transform function on each element of a sequence and returns the minimum Int32 value. (Defined by Enumerable.)
Public Extension Method Min<T>(Func<T, Nullable<Int32>>) Overloaded. Invokes a transform function on each element of a sequence and returns the minimum nullable Int32 value. (Defined by Enumerable.)
Public Extension Method Min<T>(Func<T, Int64>) Overloaded. Invokes a transform function on each element of a sequence and returns the minimum Int64 value. (Defined by Enumerable.)
Public Extension Method Min<T>(Func<T, Nullable<Int64>>) Overloaded. Invokes a transform function on each element of a sequence and returns the minimum nullable Int64 value. (Defined by Enumerable.)
Public Extension Method Min<T>(Func<T, Single>) Overloaded. Invokes a transform function on each element of a sequence and returns the minimum Single value. (Defined by Enumerable.)
Public Extension Method Min<T>(Func<T, Nullable<Single>>) Overloaded. Invokes a transform function on each element of a sequence and returns the minimum nullable Single value. (Defined by Enumerable.)
Public Extension Method Min<T, TResult>(Func<T, TResult>) Overloaded. Invokes a transform function on each element of a generic sequence and returns the minimum resulting value. (Defined by Enumerable.)
Public Extension Method OfType<TResult> Filters the elements of an IEnumerable based on a specified type. (Defined by Enumerable.)
Public Extension Method OrderBy<T, TKey>(Func<T, TKey>) Overloaded. Sorts the elements of a sequence in ascending order according to a key. (Defined by Enumerable.)
Public Extension Method OrderBy<T, TKey>(Func<T, TKey>, IComparer<TKey>) Overloaded. Sorts the elements of a sequence in ascending order by using a specified comparer. (Defined by Enumerable.)
Public Extension Method OrderByDescending<T, TKey>(Func<T, TKey>) Overloaded. Sorts the elements of a sequence in descending order according to a key. (Defined by Enumerable.)
Public Extension Method OrderByDescending<T, TKey>(Func<T, TKey>, IComparer<TKey>) Overloaded. Sorts the elements of a sequence in descending order by using a specified comparer. (Defined by Enumerable.)
Public Extension Method Reverse<T> Inverts the order of the elements in a sequence. (Defined by Enumerable.)
Public Extension Method Select<T, TResult>(Func<T, TResult>) Overloaded. Projects each element of a sequence into a new form. (Defined by Enumerable.)
Public Extension Method Select<T, TResult>(Func<T, Int32, TResult>) Overloaded. Projects each element of a sequence into a new form by incorporating the element's index. (Defined by Enumerable.)
Public Extension Method SelectMany<T, TResult>(Func<T, IEnumerable<TResult>>) Overloaded. Projects each element of a sequence to an IEnumerable<T> and flattens the resulting sequences into one sequence. (Defined by Enumerable.)
Public Extension Method SelectMany<T, TResult>(Func<T, Int32, IEnumerable<TResult>>) Overloaded. Projects 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. (Defined by Enumerable.)
Public Extension Method SelectMany<T, TCollection, TResult>(Func<T, Int32, IEnumerable<TCollection>>, Func<T, TCollection, TResult>) Overloaded. 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. (Defined by Enumerable.)
Public Extension Method SelectMany<T, TCollection, TResult>(Func<T, IEnumerable<TCollection>>, Func<T, TCollection, TResult>) Overloaded. 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. (Defined by Enumerable.)
Public Extension Method SequenceEqual<T>(IEnumerable<T>) Overloaded. Determines whether two sequences are equal by comparing the elements by using the default equality comparer for their type. (Defined by Enumerable.)
Public Extension Method SequenceEqual<T>(IEnumerable<T>, IEqualityComparer<T>) Overloaded. Determines whether two sequences are equal by comparing their elements by using a specified IEqualityComparer<T>. (Defined by Enumerable.)
Public Extension Method Single<T>() Overloaded. Returns the only element of a sequence, and throws an exception if there is not exactly one element in the sequence. (Defined by Enumerable.)
Public Extension Method Single<T>(Func<T, Boolean>) Overloaded. Returns the only element of a sequence that satisfies a specified condition, and throws an exception if more than one such element exists. (Defined by Enumerable.)
Public Extension Method SingleOrDefault<T>() Overloaded. Returns the only element of a 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. (Defined by Enumerable.)
Public Extension Method SingleOrDefault<T>(Func<T, Boolean>) Overloaded. Returns the only element of a 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. (Defined by Enumerable.)
Public Extension Method Skip<T> Bypasses a specified number of elements in a sequence and then returns the remaining elements. (Defined by Enumerable.)
Public Extension Method SkipWhile<T>(Func<T, Boolean>) Overloaded. Bypasses elements in a sequence as long as a specified condition is true and then returns the remaining elements. (Defined by Enumerable.)
Public Extension Method SkipWhile<T>(Func<T, Int32, Boolean>) Overloaded. Bypasses elements in a 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. (Defined by Enumerable.)
Public Extension Method Sum<T>(Func<T, Decimal>) Overloaded. Computes the sum of the sequence of Decimal values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Sum<T>(Func<T, Nullable<Decimal>>) Overloaded. Computes the sum of the sequence of nullable Decimal values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Sum<T>(Func<T, Double>) Overloaded. Computes the sum of the sequence of Double values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Sum<T>(Func<T, Nullable<Double>>) Overloaded. Computes the sum of the sequence of nullable Double values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Sum<T>(Func<T, Int32>) Overloaded. Computes the sum of the sequence of Int32 values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Sum<T>(Func<T, Nullable<Int32>>) Overloaded. Computes the sum of the sequence of nullable Int32 values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Sum<T>(Func<T, Int64>) Overloaded. Computes the sum of the sequence of Int64 values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Sum<T>(Func<T, Nullable<Int64>>) Overloaded. Computes the sum of the sequence of nullable Int64 values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Sum<T>(Func<T, Single>) Overloaded. Computes the sum of the sequence of Single values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Sum<T>(Func<T, Nullable<Single>>) Overloaded. Computes the sum of the sequence of nullable Single values that are obtained by invoking a transform function on each element of the input sequence. (Defined by Enumerable.)
Public Extension Method Take<T> Returns a specified number of contiguous elements from the start of a sequence. (Defined by Enumerable.)
Public Extension Method TakeWhile<T>(Func<T, Boolean>) Overloaded. Returns elements from a sequence as long as a specified condition is true. (Defined by Enumerable.)
Public Extension Method TakeWhile<T>(Func<T, Int32, Boolean>) Overloaded. Returns elements from a sequence as long as a specified condition is true. The element's index is used in the logic of the predicate function. (Defined by Enumerable.)
Public Extension Method ToArray<T> Creates an array from a IEnumerable<T>. (Defined by Enumerable.)
Public Extension Method ToDictionary<T, TKey>(Func<T, TKey>) Overloaded. Creates a Dictionary<TKey, TValue> from an IEnumerable<T> according to a specified key selector function. (Defined by Enumerable.)
Public Extension Method ToDictionary<T, TKey>(Func<T, TKey>, IEqualityComparer<TKey>) Overloaded. Creates a Dictionary<TKey, TValue> from an IEnumerable<T> according to a specified key selector function and key comparer. (Defined by Enumerable.)
Public Extension Method ToDictionary<T, TKey, TElement>(Func<T, TKey>, Func<T, TElement>) Overloaded. Creates a Dictionary<TKey, TValue> from an IEnumerable<T> according to specified key selector and element selector functions. (Defined by Enumerable.)
Public Extension Method ToDictionary<T, TKey, TElement>(Func<T, TKey>, Func<T, TElement>, IEqualityComparer<TKey>) Overloaded. Creates a Dictionary<TKey, TValue> from an IEnumerable<T> according to a specified key selector function, a comparer, and an element selector function. (Defined by Enumerable.)
Public Extension Method ToList<T> Creates a List<T> from an IEnumerable<T>. (Defined by Enumerable.)
Public Extension Method ToLookup<T, TKey>(Func<T, TKey>) Overloaded. Creates a Lookup<TKey, TElement> from an IEnumerable<T> according to a specified key selector function. (Defined by Enumerable.)
Public Extension Method ToLookup<T, TKey>(Func<T, TKey>, IEqualityComparer<TKey>) Overloaded. Creates a Lookup<TKey, TElement> from an IEnumerable<T> according to a specified key selector function and key comparer. (Defined by Enumerable.)
Public Extension Method ToLookup<T, TKey, TElement>(Func<T, TKey>, Func<T, TElement>) Overloaded. Creates a Lookup<TKey, TElement> from an IEnumerable<T> according to specified key selector and element selector functions. (Defined by Enumerable.)
Public Extension Method ToLookup<T, TKey, TElement>(Func<T, TKey>, Func<T, TElement>, IEqualityComparer<TKey>) Overloaded. Creates a Lookup<TKey, TElement> from an IEnumerable<T> according to a specified key selector function, a comparer and an element selector function. (Defined by Enumerable.)
Public Extension Method Union<T>(IEnumerable<T>) Overloaded. Produces the set union of two sequences by using the default equality comparer. (Defined by Enumerable.)
Public Extension Method Union<T>(IEnumerable<T>, IEqualityComparer<T>) Overloaded. Produces the set union of two sequences by using a specified IEqualityComparer<T>. (Defined by Enumerable.)
Public Extension Method Where<T>(Func<T, Boolean>) Overloaded. Filters a sequence of values based on a predicate. (Defined by Enumerable.)
Public Extension Method Where<T>(Func<T, Int32, Boolean>) Overloaded. Filters a sequence of values based on a predicate. Each element's index is used in the logic of the predicate function. (Defined by Enumerable.)
Public Extension Method Zip<T, TSecond, TResult> Merges two sequences by using the specified predicate function. (Defined by Enumerable.)

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Explicit Interface Implementations

  Name Description
Explicit interface implemetationPrivate method ICollection<T>.Add Adds an item to an ICollection<T> object.
Explicit interface implemetationPrivate property ICollection<T>.IsReadOnly Gets a value indicating whether a collection is read-only.
Explicit interface implemetationPrivate method IEnumerable<T>.GetEnumerator Returns an enumerator that iterates through a collection.
Explicit interface implemetationPrivate method IEnumerable.GetEnumerator Returns an enumerator that iterates through a collection.

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Remarks

The HashSet<T> class provides high performance set operations. A set is a collection that contains no duplicate elements, and whose elements are in no particular order.

The capacity of a HashSet<T> object is the number of elements that the object can hold. A HashSet<T> object's capacity automatically increases as elements are added to the object.

The HashSet<T> class implements the ISet<T> interface.

Version Information

Silverlight

Supported in: 5, 4

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Thread Safety

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