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Class EnumerableExtensions

Extensions for enumerable sources

Inheritance

object

Namespace: Umbraco.Extensions

Assembly: Umbraco.Core.dll

Syntax

public static class EnumerableExtensions

Methods

ContainsAll<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)

Returns true if all items in the other collection exist in this collection

Declaration

public static bool ContainsAll<TSource>(this IEnumerable<TSource> source, IEnumerable<TSource> other)

Parameters

Type	Name	Description
IEnumerable<TSource>	source
IEnumerable<TSource>	other

Returns

Type	Description
bool

Type Parameters

Name	Description
TSource

ContainsAny<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)

Returns true if the source contains any of the items in the other list

Declaration

public static bool ContainsAny<TSource>(this IEnumerable<TSource> source, IEnumerable<TSource> other)

Parameters

Type	Name	Description
IEnumerable<TSource>	source
IEnumerable<TSource>	other

Returns

Type	Description
bool

Type Parameters

Name	Description
TSource

EmptyNull<T>(IEnumerable<T>?)

Gets a null IEnumerable as an empty IEnumerable.

Declaration

public static IEnumerable<T> EmptyNull<T>(this IEnumerable<T>? items)

Parameters

Type	Name	Description
IEnumerable<T>	items

Returns

Type	Description
IEnumerable<T>

Type Parameters

Name	Description
T

FindIndex<T>(IEnumerable<T>, Func<T, bool>)

Finds the index of the first item matching an expression in an enumerable.

Declaration

public static int FindIndex<T>(this IEnumerable<T> items, Func<T, bool> predicate)

Parameters

Type	Name	Description
IEnumerable<T>	items	The enumerable to search.
Func<T, bool>	predicate	The expression to test the items against.

Returns

Type	Description
int	The index of the first matching item, or -1.

Type Parameters

Name	Description
T	The type of the enumerated objects.

FindIndex<T>(IEnumerable<T>, int, Func<T, bool>)

Finds the index of the first item matching an expression in an enumerable.

Declaration

public static int FindIndex<T>(this IEnumerable<T> items, int startIndex, Func<T, bool> predicate)

Parameters

Type	Name	Description
IEnumerable<T>	items	The enumerable to search.
int	startIndex	The index to start at.
Func<T, bool>	predicate	The expression to test the items against.

Returns

Type	Description
int	The index of the first matching item, or -1.

Type Parameters

Name	Description
T	The type of the enumerated objects.

ForAllThatAre<TBase, TActual>(IEnumerable<TBase>, Action<TActual>)

Applies a projection action to all items in the sequence that are of the specified actual type.

Declaration

public static IEnumerable<TBase> ForAllThatAre<TBase, TActual>(this IEnumerable<TBase> sequence, Action<TActual> projection) where TActual : class

Parameters

Type	Name	Description
IEnumerable<TBase>	sequence	The source sequence.
Action<TActual>	projection	The action to apply to each item of the actual type.

Returns

Type	Description
IEnumerable<TBase>	The original sequence, allowing chaining.

Type Parameters

Name	Description
TBase	The base type of items in the sequence.
TActual	The actual type to filter and apply the projection to.

IfNotNull<TItem>(IEnumerable<TItem>, Action<TItem>)

The if not null.

Declaration

public static void IfNotNull<TItem>(this IEnumerable<TItem> items, Action<TItem> action) where TItem : class

Parameters

Type	Name	Description
IEnumerable<TItem>	items	The items.
Action<TItem>	action	The action.

Type Parameters

Name	Description
TItem	The type

InGroupsOf<T>(IEnumerable<T>?, int)

Splits the enumerable into groups of the specified size.

Declaration

public static IEnumerable<IEnumerable<T>> InGroupsOf<T>(this IEnumerable<T>? source, int groupSize)

Parameters

Type	Name	Description
IEnumerable<T>	source	The source enumerable.
int	groupSize	The size of each group.

Returns

Type	Description
IEnumerable<IEnumerable<T>>	An enumerable of groups, each containing up to the specified number of items.

Type Parameters

Name	Description
T	The type of items in the enumerable.

Exceptions

Type	Condition
ArgumentNullException	Thrown when source is null.
ArgumentException	Thrown when groupSize is less than or equal to zero.

IndexOf<T>(IEnumerable<T>, T)

Finds the index of the first occurrence of an item in an enumerable.

Declaration

public static int IndexOf<T>(this IEnumerable<T> items, T item)

Parameters

Type	Name	Description
IEnumerable<T>	items	The enumerable to search.
T	item	The item to find.

Returns

Type	Description
int	The index of the first matching item, or -1 if the item was not found.

Type Parameters

Name	Description
T

IsCollectionEmpty<T>(IReadOnlyCollection<T>?)

Determines whether the collection is null or empty.

Declaration

public static bool IsCollectionEmpty<T>(this IReadOnlyCollection<T>? list)

Parameters

Type	Name	Description
IReadOnlyCollection<T>	list	The collection to check.

Returns

Type	Description
bool	true if the collection is null or empty; otherwise, false.

Type Parameters

Name	Description
T	The type of items in the collection.

OfTypes<T>(IEnumerable<T>, params Type[])

Filters a sequence to include only items whose type is in the specified list of types.

Declaration

public static IEnumerable<T> OfTypes<T>(this IEnumerable<T> contents, params Type[] types)

Parameters

Type	Name	Description
IEnumerable<T>	contents	The source sequence.
Type[]	types	The types to include.

Returns

Type	Description
IEnumerable<T>	A filtered sequence containing only items of the specified types.

Type Parameters

Name	Description
T	The type of items in the sequence.

Remarks

This is similar to .OfType<T>() but supports filtering with multiple types.

OrderBy<TSource, TKey>(IEnumerable<TSource>, Func<TSource, TKey>, Direction)

Orders the elements of a sequence according to a key and the specified sort direction.

Declaration

public static IOrderedEnumerable<TSource> OrderBy<TSource, TKey>(this IEnumerable<TSource> source, Func<TSource, TKey> keySelector, Direction sortOrder)

Parameters

Type	Name	Description
IEnumerable<TSource>	source	A sequence of values to order.
Func<TSource, TKey>	keySelector	A function to extract a key from an element.
Direction	sortOrder	The direction to sort (ascending or descending).

Returns

Type	Description
IOrderedEnumerable<TSource>	An ordered enumerable.

Type Parameters

Name	Description
TSource	The type of the elements of source.
TKey	The type of the key returned by keySelector.

Range<T>(Func<int, T>, int)

Returns a sequence of length count whose elements are the result of invoking factory.

Declaration

public static IEnumerable<T> Range<T>(Func<int, T> factory, int count)

Parameters

Type	Name	Description
Func<int, T>	factory	The factory.
int	count	The count.

Returns

Type	Description
IEnumerable<T>

Type Parameters

Name	Description
T

RemoveAll<T>(ICollection<T>, Func<T, bool>)

Removes all matching items from an System.Collections.Generic.ICollection<T>.

Declaration

public static void RemoveAll<T>(this ICollection<T> list, Func<T, bool> predicate)

Parameters

Type	Name	Description
ICollection<T>	list	The list.
Func<T, bool>	predicate	The predicate.

Type Parameters

Name	Description
T

RemoveAll<T>(IList<T>, Func<T, bool>)

Removes all matching items from an System.Collections.Generic.IList<T>.

Declaration

public static void RemoveAll<T>(this IList<T> list, Func<T, bool> predicate)

Parameters

Type	Name	Description
IList<T>	list	The list.
Func<T, bool>	predicate	The predicate.

Type Parameters

Name	Description
T

SelectByGroups<TResult, TSource>(IEnumerable<TSource>, Func<IEnumerable<TSource>, IEnumerable<TResult>>, int)

Selects items by processing the source in groups of the specified size.

Declaration

public static IEnumerable<TResult> SelectByGroups<TResult, TSource>(this IEnumerable<TSource> source, Func<IEnumerable<TSource>, IEnumerable<TResult>> selector, int groupSize)

Parameters

Type	Name	Description
IEnumerable<TSource>	source	The source enumerable.
Func<IEnumerable<TSource>, IEnumerable<TResult>>	selector	The selector function to apply to each group.
int	groupSize	The size of each group.

Returns

Type	Description
IEnumerable<TResult>	An enumerable of results from processing each group.

Type Parameters

Name	Description
TResult	The type of the result items.
TSource	The type of the source items.

SelectRecursive<TSource>(IEnumerable<TSource>, Func<TSource, IEnumerable<TSource>>, int)

Recursively selects items from the source using the specified selector.

Declaration

public static IEnumerable<TSource> SelectRecursive<TSource>(this IEnumerable<TSource> source, Func<TSource, IEnumerable<TSource>> recursiveSelector, int maxRecusionDepth = 100)

Parameters

Type	Name	Description
IEnumerable<TSource>	source	The source enumerable.
Func<TSource, IEnumerable<TSource>>	recursiveSelector	A function that returns child elements for each item.
int	maxRecusionDepth	The maximum recursion depth to prevent stack overflow.

Returns

Type	Description
IEnumerable<TSource>	A flattened enumerable of all items and their recursive children.

Type Parameters

Name	Description
TSource	The type of the source items.

Exceptions

Type	Condition
InvalidOperationException	Thrown when the maximum recursion depth is exceeded.

SkipLast<T>(IEnumerable<T>)

Returns all elements of the sequence except the last one.

Declaration

public static IEnumerable<T> SkipLast<T>(this IEnumerable<T> source)

Parameters

Type	Name	Description
IEnumerable<T>	source	The source enumerable.

Returns

Type	Description
IEnumerable<T>	An enumerable containing all elements except the last.

Type Parameters

Name	Description
T	The type of items in the enumerable.

Transform<TSource, TTarget>(IEnumerable<TSource>, Func<IEnumerable<TSource>, IEnumerable<TTarget>>)

Transforms an enumerable.

Declaration

public static IEnumerable<TTarget> Transform<TSource, TTarget>(this IEnumerable<TSource> source, Func<IEnumerable<TSource>, IEnumerable<TTarget>> transform)

Parameters

Type	Name	Description
IEnumerable<TSource>	source
Func<IEnumerable<TSource>, IEnumerable<TTarget>>	transform

Returns

Type	Description
IEnumerable<TTarget>

Type Parameters

Name	Description
TSource
TTarget

UnsortedSequenceEqual<T>(IEnumerable<T>?, IEnumerable<T>?)

Determines if 2 lists have equal elements within them regardless of how they are sorted

Declaration

public static bool UnsortedSequenceEqual<T>(this IEnumerable<T>? source, IEnumerable<T>? other)

Parameters

Type	Name	Description
IEnumerable<T>	source
IEnumerable<T>	other

Returns

Type	Description
bool

Type Parameters

Name	Description
T

Remarks

The logic for this is taken from: http://stackoverflow.com/questions/4576723/test-whether-two-ienumerablet-have-the-same-values-with-the-same-frequencies There's a few answers, this one seems the best for it's simplicity and based on the comment of Eamon

WhereNotNull<T>(IEnumerable<T?>)

Filters a sequence of values to ignore those which are null.

Declaration

public static IEnumerable<T> WhereNotNull<T>(this IEnumerable<T?> coll) where T : class

Parameters

Type	Name	Description
IEnumerable<T>	coll	The coll.

Returns

Type	Description
IEnumerable<T>

Type Parameters

Name	Description
T

Yield<T>(T)

Wraps this object instance into an IEnumerable{T} consisting of a single item.

Declaration

public static IEnumerable<T> Yield<T>(this T item)

Parameters

Type	Name	Description
T	item	The instance that will be wrapped.

Returns

Type	Description
IEnumerable<T>	An IEnumerable{T} consisting of a single item.

Type Parameters

Name	Description
T	Type of the object.