ILookup<TKey,TElement> Interface
Definition
Defines an indexer, size property, and Boolean search method for data structures that map keys to IEnumerable<T> sequences of values.
generic <typename TKey, typename TElement>
public interface class ILookup : System::Collections::Generic::IEnumerable<System::Linq::IGrouping<TKey, TElement> ^>
public interface ILookup<TKey,TElement> : System.Collections.Generic.IEnumerable<System.Linq.IGrouping<TKey,TElement>>
type ILookup<'Key, 'Element> = interface
interface seq<IGrouping<'Key, 'Element>>
interface IEnumerable
Public Interface ILookup(Of TKey, TElement)
Implements IEnumerable(Of IGrouping(Of TKey, TElement))
Type Parameters
- TKey
The type of the keys in the ILookup<TKey,TElement>.
- TElement
The type of the elements in the IEnumerable<T> sequences that make up the values in the ILookup<TKey,TElement>.
- Derived
- Implements
-
IEnumerable<IGrouping<TKey,TElement>> IEnumerable
Examples
The following code example creates an ILookup<TKey,TElement> object and iterates through its contents.
class Package
{
public string Company { get; set; }
public double Weight { get; set; }
public long TrackingNumber { get; set; }
}
public static void ILookupExample()
{
// Create a list of Packages to put into an ILookup data structure.
List<Package> packages = new List<Package> { new Package { Company = "Coho Vineyard", Weight = 25.2, TrackingNumber = 89453312L },
new Package { Company = "Lucerne Publishing", Weight = 18.7, TrackingNumber = 89112755L },
new Package { Company = "Wingtip Toys", Weight = 6.0, TrackingNumber = 299456122L },
new Package { Company = "Contoso Pharmaceuticals", Weight = 9.3, TrackingNumber = 670053128L },
new Package { Company = "Wide World Importers", Weight = 33.8, TrackingNumber = 4665518773L } };
// Create a Lookup to organize the packages. Use the first character of Company as the key value.
// Select Company appended to TrackingNumber for each element value in the ILookup object.
ILookup<char, string> packageLookup = packages.ToLookup(
p => Convert.ToChar(p.Company.Substring(0, 1)),
p => p.Company + " " + p.TrackingNumber
);
// Iterate through each value in the ILookup and output the contents.
foreach (var packageGroup in packageLookup)
{
// Print the key value.
Console.WriteLine(packageGroup.Key);
// Iterate through each value in the collection.
foreach (string str in packageGroup)
Console.WriteLine(" {0}", str);
}
// This code produces the following output:
//
// C
// Coho Vineyard 89453312
// Contoso Pharmaceuticals 670053128
// L
// Lucerne Publishing 89112755
// W
// Wingtip Toys 299456122
// Wide World Importers 4665518773
}
Structure Package
Public Company As String
Public Weight As Double
Public TrackingNumber As Long
End Structure
Sub ILookupExample()
' Create a list of Packages to put into an ILookup data structure.
Dim packages As New System.Collections.Generic.List(Of Package)(New Package() _
{New Package With {.Company = "Coho Vineyard", .Weight = 25.2, .TrackingNumber = 89453312L}, _
New Package With {.Company = "Lucerne Publishing", .Weight = 18.7, .TrackingNumber = 89112755L}, _
New Package With {.Company = "Wingtip Toys", .Weight = 6.0, .TrackingNumber = 299456122L}, _
New Package With {.Company = "Contoso Pharmaceuticals", .Weight = 9.3, .TrackingNumber = 670053128L}, _
New Package With {.Company = "Wide World Importers", .Weight = 33.8, .TrackingNumber = 4665518773L}})
' Create a ILookup to organize the packages. Use the first character of Company as the key value.
' Select Company appended to TrackingNumber for each element value.
Dim packageLookup As ILookup(Of Char, String) = _
packages.ToLookup(Function(p) Convert.ToChar(p.Company.Substring(0, 1)), _
Function(p) p.Company & " " & p.TrackingNumber)
Dim output As New System.Text.StringBuilder
' Iterate through each group in the Lookup and output the contents.
For Each packageGroup In packageLookup
' Print the key value.
output.AppendLine(packageGroup.Key)
' Iterate through each value in the group and output it.
For Each str As String In packageGroup
output.AppendLine(String.Format(" {0}", str))
Next
Next
' Display the output.
MsgBox(output.ToString())
' This code produces the following output:
'
' C
' Coho Vineyard 89453312
' Contoso Pharmaceuticals 670053128
' L
' Lucerne Publishing 89112755
' W
' Wingtip Toys 299456122
' Wide World Importers 4665518773
End Sub
Remarks
The type Lookup<TKey,TElement> implements the ILookup<TKey,TElement> interface.
The extension method ToLookup, which can be appended to the end of a LINQ query, returns an object of type ILookup<TKey,TElement>.
Properties
Count |
Gets the number of key/value collection pairs in the ILookup<TKey,TElement>. |
Item[TKey] |
Gets the IEnumerable<T> sequence of values indexed by a specified key. |
Methods
Contains(TKey) |
Determines whether a specified key exists in the ILookup<TKey,TElement>. |
GetEnumerator() |
Returns an enumerator that iterates through a collection. (Inherited from IEnumerable) |
Extension Methods
ToImmutableArray<TSource>(IEnumerable<TSource>) |
Creates an immutable array from the specified collection. |
ToImmutableDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>) |
Constructs an immutable dictionary from an existing collection of elements, applying a transformation function to the source keys. |
ToImmutableDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>) |
Constructs an immutable dictionary based on some transformation of a sequence. |
ToImmutableDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>) |
Enumerates and transforms a sequence, and produces an immutable dictionary of its contents. |
ToImmutableDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>, IEqualityComparer<TKey>) |
Enumerates and transforms a sequence, and produces an immutable dictionary of its contents by using the specified key comparer. |
ToImmutableDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>, IEqualityComparer<TKey>, IEqualityComparer<TValue>) |
Enumerates and transforms a sequence, and produces an immutable dictionary of its contents by using the specified key and value comparers. |
ToImmutableHashSet<TSource>(IEnumerable<TSource>) |
Enumerates a sequence and produces an immutable hash set of its contents. |
ToImmutableHashSet<TSource>(IEnumerable<TSource>, IEqualityComparer<TSource>) |
Enumerates a sequence, produces an immutable hash set of its contents, and uses the specified equality comparer for the set type. |
ToImmutableList<TSource>(IEnumerable<TSource>) |
Enumerates a sequence and produces an immutable list of its contents. |
ToImmutableSortedDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>) |
Enumerates and transforms a sequence, and produces an immutable sorted dictionary of its contents. |
ToImmutableSortedDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>, IComparer<TKey>) |
Enumerates and transforms a sequence, and produces an immutable sorted dictionary of its contents by using the specified key comparer. |
ToImmutableSortedDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>, IComparer<TKey>, IEqualityComparer<TValue>) |
Enumerates and transforms a sequence, and produces an immutable sorted dictionary of its contents by using the specified key and value comparers. |
ToImmutableSortedSet<TSource>(IEnumerable<TSource>) |
Enumerates a sequence and produces an immutable sorted set of its contents. |
ToImmutableSortedSet<TSource>(IEnumerable<TSource>, IComparer<TSource>) |
Enumerates a sequence, produces an immutable sorted set of its contents, and uses the specified comparer. |
CopyToDataTable<T>(IEnumerable<T>) |
Returns a DataTable that contains copies of the DataRow objects, given an input IEnumerable<T> object where the generic parameter |
CopyToDataTable<T>(IEnumerable<T>, DataTable, LoadOption) |
Copies DataRow objects to the specified DataTable, given an input IEnumerable<T> object where the generic parameter |
CopyToDataTable<T>(IEnumerable<T>, DataTable, LoadOption, FillErrorEventHandler) |
Copies DataRow objects to the specified DataTable, given an input IEnumerable<T> object where the generic parameter |
Aggregate<TSource>(IEnumerable<TSource>, Func<TSource,TSource,TSource>) |
Applies an accumulator function over a sequence. |
Aggregate<TSource,TAccumulate>(IEnumerable<TSource>, TAccumulate, Func<TAccumulate,TSource,TAccumulate>) |
Applies an accumulator function over a sequence. The specified seed value is used as the initial accumulator value. |
Aggregate<TSource,TAccumulate,TResult>(IEnumerable<TSource>, TAccumulate, Func<TAccumulate,TSource,TAccumulate>, Func<TAccumulate,TResult>) |
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. |
All<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) |
Determines whether all elements of a sequence satisfy a condition. |
Any<TSource>(IEnumerable<TSource>) |
Determines whether a sequence contains any elements. |
Any<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) |
Determines whether any element of a sequence satisfies a condition. |
Append<TSource>(IEnumerable<TSource>, TSource) |
Appends a value to the end of the sequence. |
AsEnumerable<TSource>(IEnumerable<TSource>) |
Returns the input typed as IEnumerable<T>. |
Average<TSource>(IEnumerable<TSource>, Func<TSource,Decimal>) |
Computes the average of a sequence of Decimal values that are obtained by invoking a transform function on each element of the input sequence. |
Average<TSource>(IEnumerable<TSource>, Func<TSource,Double>) |
Computes the average of a sequence of Double values that are obtained by invoking a transform function on each element of the input sequence. |
Average<TSource>(IEnumerable<TSource>, Func<TSource,Int32>) |
Computes the average of a sequence of Int32 values that are obtained by invoking a transform function on each element of the input sequence. |
Average<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) |
Computes the average of a sequence of Int64 values that are obtained by invoking a transform function on each element of the input sequence. |
Average<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Decimal>>) |
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. |
Average<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Double>>) |
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. |
Average<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int32>>) |
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. |
Average<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int64>>) |
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. |
Average<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Single>>) |
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. |
Average<TSource>(IEnumerable<TSource>, Func<TSource,Single>) |
Computes the average of a sequence of Single values that are obtained by invoking a transform function on each element of the input sequence. |
Cast<TResult>(IEnumerable) |
Casts the elements of an IEnumerable to the specified type. |
Concat<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) |
Concatenates two sequences. |
Contains<TSource>(IEnumerable<TSource>, TSource) |
Determines whether a sequence contains a specified element by using the default equality comparer. |
Contains<TSource>(IEnumerable<TSource>, TSource, IEqualityComparer<TSource>) |
Determines whether a sequence contains a specified element by using a specified IEqualityComparer<T>. |
Count<TSource>(IEnumerable<TSource>) |
Returns the number of elements in a sequence. |
Count<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) |
Returns a number that represents how many elements in the specified sequence satisfy a condition. |
DefaultIfEmpty<TSource>(IEnumerable<TSource>) |
Returns the elements of the specified sequence or the type parameter's default value in a singleton collection if the sequence is empty. |
DefaultIfEmpty<TSource>(IEnumerable<TSource>, TSource) |
Returns the elements of the specified sequence or the specified value in a singleton collection if the sequence is empty. |
Distinct<TSource>(IEnumerable<TSource>) |
Returns distinct elements from a sequence by using the default equality comparer to compare values. |
Distinct<TSource>(IEnumerable<TSource>, IEqualityComparer<TSource>) |
Returns distinct elements from a sequence by using a specified IEqualityComparer<T> to compare values. |
ElementAt<TSource>(IEnumerable<TSource>, Int32) |
Returns the element at a specified index in a sequence. |
ElementAtOrDefault<TSource>(IEnumerable<TSource>, Int32) |
Returns the element at a specified index in a sequence or a default value if the index is out of range. |
Except<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) |
Produces the set difference of two sequences by using the default equality comparer to compare values. |
Except<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>) |
Produces the set difference of two sequences by using the specified IEqualityComparer<T> to compare values. |
First<TSource>(IEnumerable<TSource>) |
Returns the first element of a sequence. |
First<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) |
Returns the first element in a sequence that satisfies a specified condition. |
FirstOrDefault<TSource>(IEnumerable<TSource>) |
Returns the first element of a sequence, or a default value if the sequence contains no elements. |
FirstOrDefault<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) |
Returns the first element of the sequence that satisfies a condition or a default value if no such element is found. |
GroupBy<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>) |
Groups the elements of a sequence according to a specified key selector function. |
GroupBy<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>) |
Groups the elements of a sequence according to a specified key selector function and compares the keys by using a specified comparer. |
GroupBy<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>) |
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. |
GroupBy<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>) |
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. |
GroupBy<TSource,TKey,TResult>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TKey,IEnumerable<TSource>,TResult>) |
Groups 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>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TKey,IEnumerable<TSource>,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. The keys are compared by using a specified comparer. |
GroupBy<TSource,TKey,TElement,TResult>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, Func<TKey,IEnumerable<TElement>,TResult>) |
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. |
GroupBy<TSource,TKey,TElement,TResult>(IEnumerable<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>(IEnumerable<TOuter>, IEnumerable<TInner>, Func<TOuter,TKey>, Func<TInner,TKey>, Func<TOuter,IEnumerable<TInner>,TResult>) |
Correlates 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>(IEnumerable<TOuter>, IEnumerable<TInner>, Func<TOuter,TKey>, Func<TInner,TKey>, Func<TOuter,IEnumerable<TInner>,TResult>, IEqualityComparer<TKey>) |
Correlates the elements of two sequences based on key equality and groups the results. A specified IEqualityComparer<T> is used to compare keys. |
Intersect<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) |
Produces the set intersection of two sequences by using the default equality comparer to compare values. |
Intersect<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>) |
Produces the set intersection of two sequences by using the specified IEqualityComparer<T> to compare values. |
Join<TOuter,TInner,TKey,TResult>(IEnumerable<TOuter>, IEnumerable<TInner>, Func<TOuter,TKey>, Func<TInner,TKey>, Func<TOuter,TInner,TResult>) |
Correlates the elements of two sequences based on matching keys. The default equality comparer is used to compare keys. |
Join<TOuter,TInner,TKey,TResult>(IEnumerable<TOuter>, IEnumerable<TInner>, Func<TOuter,TKey>, Func<TInner,TKey>, Func<TOuter,TInner,TResult>, IEqualityComparer<TKey>) |
Correlates the elements of two sequences based on matching keys. A specified IEqualityComparer<T> is used to compare keys. |
Last<TSource>(IEnumerable<TSource>) |
Returns the last element of a sequence. |
Last<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) |
Returns the last element of a sequence that satisfies a specified condition. |
LastOrDefault<TSource>(IEnumerable<TSource>) |
Returns the last element of a sequence, or a default value if the sequence contains no elements. |
LastOrDefault<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) |
Returns the last element of a sequence that satisfies a condition or a default value if no such element is found. |
LongCount<TSource>(IEnumerable<TSource>) |
Returns an Int64 that represents the total number of elements in a sequence. |
LongCount<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) |
Returns an Int64 that represents how many elements in a sequence satisfy a condition. |
Max<TSource>(IEnumerable<TSource>) |
Returns the maximum value in a generic sequence. |
Max<TSource>(IEnumerable<TSource>, Func<TSource,Decimal>) |
Invokes a transform function on each element of a sequence and returns the maximum Decimal value. |
Max<TSource>(IEnumerable<TSource>, Func<TSource,Double>) |
Invokes a transform function on each element of a sequence and returns the maximum Double value. |
Max<TSource>(IEnumerable<TSource>, Func<TSource,Int32>) |
Invokes a transform function on each element of a sequence and returns the maximum Int32 value. |
Max<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) |
Invokes a transform function on each element of a sequence and returns the maximum Int64 value. |
Max<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Decimal>>) |
Invokes a transform function on each element of a sequence and returns the maximum nullable Decimal value. |
Max<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Double>>) |
Invokes a transform function on each element of a sequence and returns the maximum nullable Double value. |
Max<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int32>>) |
Invokes a transform function on each element of a sequence and returns the maximum nullable Int32 value. |
Max<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int64>>) |
Invokes a transform function on each element of a sequence and returns the maximum nullable Int64 value. |
Max<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Single>>) |
Invokes a transform function on each element of a sequence and returns the maximum nullable Single value. |
Max<TSource>(IEnumerable<TSource>, Func<TSource,Single>) |
Invokes a transform function on each element of a sequence and returns the maximum Single value. |
Max<TSource,TResult>(IEnumerable<TSource>, Func<TSource,TResult>) |
Invokes a transform function on each element of a generic sequence and returns the maximum resulting value. |
Min<TSource>(IEnumerable<TSource>) |
Returns the minimum value in a generic sequence. |
Min<TSource>(IEnumerable<TSource>, Func<TSource,Decimal>) |
Invokes a transform function on each element of a sequence and returns the minimum Decimal value. |
Min<TSource>(IEnumerable<TSource>, Func<TSource,Double>) |
Invokes a transform function on each element of a sequence and returns the minimum Double value. |
Min<TSource>(IEnumerable<TSource>, Func<TSource,Int32>) |
Invokes a transform function on each element of a sequence and returns the minimum Int32 value. |
Min<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) |
Invokes a transform function on each element of a sequence and returns the minimum Int64 value. |
Min<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Decimal>>) |
Invokes a transform function on each element of a sequence and returns the minimum nullable Decimal value. |
Min<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Double>>) |
Invokes a transform function on each element of a sequence and returns the minimum nullable Double value. |
Min<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int32>>) |
Invokes a transform function on each element of a sequence and returns the minimum nullable Int32 value. |
Min<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int64>>) |
Invokes a transform function on each element of a sequence and returns the minimum nullable Int64 value. |
Min<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Single>>) |
Invokes a transform function on each element of a sequence and returns the minimum nullable Single value. |
Min<TSource>(IEnumerable<TSource>, Func<TSource,Single>) |
Invokes a transform function on each element of a sequence and returns the minimum Single value. |
Min<TSource,TResult>(IEnumerable<TSource>, Func<TSource,TResult>) |
Invokes a transform function on each element of a generic sequence and returns the minimum resulting value. |
OfType<TResult>(IEnumerable) |
Filters the elements of an IEnumerable based on a specified type. |
OrderBy<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>) |
Sorts the elements of a sequence in ascending order according to a key. |
OrderBy<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IComparer<TKey>) |
Sorts the elements of a sequence in ascending order by using a specified comparer. |
OrderByDescending<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>) |
Sorts the elements of a sequence in descending order according to a key. |
OrderByDescending<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IComparer<TKey>) |
Sorts the elements of a sequence in descending order by using a specified comparer. |
Prepend<TSource>(IEnumerable<TSource>, TSource) |
Adds a value to the beginning of the sequence. |
Reverse<TSource>(IEnumerable<TSource>) |
Inverts the order of the elements in a sequence. |
Select<TSource,TResult>(IEnumerable<TSource>, Func<TSource,TResult>) |
Projects each element of a sequence into a new form. |
Select<TSource,TResult>(IEnumerable<TSource>, Func<TSource,Int32,TResult>) |
Projects each element of a sequence into a new form by incorporating the element's index. |
SelectMany<TSource,TResult>(IEnumerable<TSource>, Func<TSource,IEnumerable<TResult>>) |
Projects each element of a sequence to an IEnumerable<T> and flattens the resulting sequences into one sequence. |
SelectMany<TSource,TResult>(IEnumerable<TSource>, Func<TSource,Int32,IEnumerable<TResult>>) |
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. |
SelectMany<TSource,TCollection,TResult>(IEnumerable<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>(IEnumerable<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>(IEnumerable<TSource>, IEnumerable<TSource>) |
Determines whether two sequences are equal by comparing the elements by using the default equality comparer for their type. |
SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>) |
Determines whether two sequences are equal by comparing their elements by using a specified IEqualityComparer<T>. |
Single<TSource>(IEnumerable<TSource>) |
Returns the only element of a sequence, and throws an exception if there is not exactly one element in the sequence. |
Single<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) |
Returns the only element of a sequence that satisfies a specified condition, and throws an exception if more than one such element exists. |
SingleOrDefault<TSource>(IEnumerable<TSource>) |
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. |
SingleOrDefault<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) |
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. |
Skip<TSource>(IEnumerable<TSource>, Int32) |
Bypasses a specified number of elements in a sequence and then returns the remaining elements. |
SkipLast<TSource>(IEnumerable<TSource>, Int32) |
Returns a new enumerable collection that contains the elements from |
SkipWhile<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) |
Bypasses elements in a sequence as long as a specified condition is true and then returns the remaining elements. |
SkipWhile<TSource>(IEnumerable<TSource>, Func<TSource,Int32,Boolean>) |
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. |
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Decimal>) |
Computes the sum of the sequence of Decimal values that are obtained by invoking a transform function on each element of the input sequence. |
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Double>) |
Computes the sum of the sequence of Double values that are obtained by invoking a transform function on each element of the input sequence. |
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Int32>) |
Computes the sum of the sequence of Int32 values that are obtained by invoking a transform function on each element of the input sequence. |
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Int64>) |
Computes the sum of the sequence of Int64 values that are obtained by invoking a transform function on each element of the input sequence. |
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Decimal>>) |
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. |
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Double>>) |
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. |
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int32>>) |
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. |
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Int64>>) |
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. |
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Nullable<Single>>) |
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. |
Sum<TSource>(IEnumerable<TSource>, Func<TSource,Single>) |
Computes the sum of the sequence of Single values that are obtained by invoking a transform function on each element of the input sequence. |
Take<TSource>(IEnumerable<TSource>, Int32) |
Returns a specified number of contiguous elements from the start of a sequence. |
TakeLast<TSource>(IEnumerable<TSource>, Int32) |
Returns a new enumerable collection that contains the last |
TakeWhile<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) |
Returns elements from a sequence as long as a specified condition is true. |
TakeWhile<TSource>(IEnumerable<TSource>, Func<TSource,Int32,Boolean>) |
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. |
ToArray<TSource>(IEnumerable<TSource>) |
Creates an array from a IEnumerable<T>. |
ToDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>) |
Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to a specified key selector function. |
ToDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>) |
Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to a specified key selector function and key comparer. |
ToDictionary<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>) |
Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to specified key selector and element selector functions. |
ToDictionary<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>) |
Creates a Dictionary<TKey,TValue> from an IEnumerable<T> according to a specified key selector function, a comparer, and an element selector function. |
ToHashSet<TSource>(IEnumerable<TSource>) |
Creates a HashSet<T> from an IEnumerable<T>. |
ToHashSet<TSource>(IEnumerable<TSource>, IEqualityComparer<TSource>) |
Creates a HashSet<T> from an IEnumerable<T> using the |
ToList<TSource>(IEnumerable<TSource>) |
Creates a List<T> from an IEnumerable<T>. |
ToLookup<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>) |
Creates a Lookup<TKey,TElement> from an IEnumerable<T> according to a specified key selector function. |
ToLookup<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>) |
Creates a Lookup<TKey,TElement> from an IEnumerable<T> according to a specified key selector function and key comparer. |
ToLookup<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>) |
Creates a Lookup<TKey,TElement> from an IEnumerable<T> according to specified key selector and element selector functions. |
ToLookup<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>) |
Creates a Lookup<TKey,TElement> from an IEnumerable<T> according to a specified key selector function, a comparer and an element selector function. |
Union<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) |
Produces the set union of two sequences by using the default equality comparer. |
Union<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>) |
Produces the set union of two sequences by using a specified IEqualityComparer<T>. |
Where<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) |
Filters a sequence of values based on a predicate. |
Where<TSource>(IEnumerable<TSource>, Func<TSource,Int32,Boolean>) |
Filters a sequence of values based on a predicate. Each element's index is used in the logic of the predicate function. |
Zip<TFirst,TSecond>(IEnumerable<TFirst>, IEnumerable<TSecond>) |
Produces a sequence of tuples with elements from the two specified sequences. |
Zip<TFirst,TSecond,TResult>(IEnumerable<TFirst>, IEnumerable<TSecond>, Func<TFirst,TSecond,TResult>) |
Applies a specified function to the corresponding elements of two sequences, producing a sequence of the results. |
AsParallel(IEnumerable) |
Enables parallelization of a query. |
AsParallel<TSource>(IEnumerable<TSource>) |
Enables parallelization of a query. |
AsQueryable(IEnumerable) |
Converts an IEnumerable to an IQueryable. |
AsQueryable<TElement>(IEnumerable<TElement>) |
Converts a generic IEnumerable<T> to a generic IQueryable<T>. |
Ancestors<T>(IEnumerable<T>) |
Returns a collection of elements that contains the ancestors of every node in the source collection. |
Ancestors<T>(IEnumerable<T>, XName) |
Returns a filtered collection of elements that contains the ancestors of every node in the source collection. Only elements that have a matching XName are included in the collection. |
DescendantNodes<T>(IEnumerable<T>) |
Returns a collection of the descendant nodes of every document and element in the source collection. |
Descendants<T>(IEnumerable<T>) |
Returns a collection of elements that contains the descendant elements of every element and document in the source collection. |
Descendants<T>(IEnumerable<T>, XName) |
Returns a filtered collection of elements that contains the descendant elements of every element and document in the source collection. Only elements that have a matching XName are included in the collection. |
Elements<T>(IEnumerable<T>) |
Returns a collection of the child elements of every element and document in the source collection. |
Elements<T>(IEnumerable<T>, XName) |
Returns a filtered collection of the child elements of every element and document in the source collection. Only elements that have a matching XName are included in the collection. |
InDocumentOrder<T>(IEnumerable<T>) |
Returns a collection of nodes that contains all nodes in the source collection, sorted in document order. |
Nodes<T>(IEnumerable<T>) |
Returns a collection of the child nodes of every document and element in the source collection. |
Remove<T>(IEnumerable<T>) |
Removes every node in the source collection from its parent node. |