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> Unreal Engine API Reference > Runtime > Core > Containers > TArray

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TArray

Templated dynamic array

Inheritance Hierarchy

References

Module	Core
Header	/Engine/Source/Runtime/Core/Public/Containers/Array.h
Include	#include "Containers/Array.h"

Syntax

template<typename InElementType, typename InAllocatorType>
class TArray

Remarks

Templated dynamic array

A dynamically sized array of typed elements. Makes the assumption that your elements are relocate-able; i.e. that they can be transparently moved to new memory without a copy constructor. The main implication is that pointers to elements in the TArray may be invalidated by adding or removing other elements to the array. Removal of elements is O(N) and invalidates the indices of subsequent elements.

Caution: as noted below some methods are not safe for element types that require constructors.

Variables

		Name	Description
	ElementAllocato...	AllocatorInstance
	SizeType	ArrayMax
	SizeType	ArrayNum

Constructors

	Name	Description
	TArray()	Constructor, initializes element number counters.
	TArray ( TArray< OtherElementType, Allocator..., SizeType ExtraSlack )	Move constructor.
	TArray ( const TArrayView< OtherElementType,... )
	TArray ( std::initializer_list< InElementTyp... )	Initializer list constructor
	TArray ( const TArray< OtherElementType, Oth... )	Copy constructor with changed allocator. Use the common routine to perform the copy.
	TArray ( const TArray& Other )	Copy constructor. Use the common routine to perform the copy.
	TArray ( TArray&& Other )	Move constructor.
	TArray ( TArray< OtherElementType, OtherAllo... )	Move constructor.
	TArray ( const ElementType* Ptr, SizeType Count )	Constructor from a raw array of elements.
	TArray ( const TArray& Other, SizeType ExtraSlack )	Copy constructor. Use the common routine to perform the copy.

Destructors

	Name	Description
	~TArray()	Destructor.

Functions

	Name	Description
SizeType	Add ( const ElementType& Item )	Adds a new item to the end of the array, possibly reallocating the whole array to fit.
SizeType	Add ( ElementType&& Item )	Adds a new item to the end of the array, possibly reallocating the whole array to fit.
ElementType ...	Add_GetRef ( const ElementType& Item )	Adds a new item to the end of the array, possibly reallocating the whole array to fit.
ElementType ...	Add_GetRef ( ElementType&& Item )	Adds a new item to the end of the array, possibly reallocating the whole array to fit.
SizeType	AddDefaulted()	Adds new items to the end of the array, possibly reallocating the whole array to fit.
SizeType	AddDefaulted ( SizeType Count )
ElementType ...	AddDefaulted_GetRef()	Add a new item to the end of the array, possibly reallocating the whole array to fit.
SizeType	AddUninitialized ( SizeType Count )
SizeType	AddUninitialized()	Adds a given number of uninitialized elements into the array.
SizeType	AddUnique ( ElementType&& Item )	Adds unique element to array if it doesn't exist. Move semantics version.
SizeType	AddUnique ( const ElementType& Item )	Adds unique element to array if it doesn't exist.
SizeType	AddZeroed()	Adds new items to the end of the array, possibly reallocating the whole array to fit.
SizeType	AddZeroed ( SizeType Count )
ElementType ...	AddZeroed_GetRef()	Adds a new item to the end of the array, possibly reallocating the whole array to fit.
void	Append ( const TArray< OtherElementType, Oth... )	Appends the specified array to this array. AllocatorType changing version.
void	Append ( TArray< OtherElementType, OtherAllo... )	Appends the specified array to this array.
void	Append ( RangeType&& Source )	Appends the elements from a contiguous range to this array.
void	Append ( std::initializer_list< ElementType ... )	Adds an initializer list of elements to the end of the TArray.
void	Append ( const ElementType* Ptr, SizeType Count )	Adds a raw array of elements to the end of the TArray.
void	Append ( const typename TContainerElementTyp..., SizeType Count )	Adds a raw array of elements to the end of the TArray.
void	AppendHash ( const FPlatformTypeLayoutParameters..., FSHA1& Hasher )
RangedForCon...	begin()
RangedForIte...	begin()	DO NOT USE DIRECTLY STL-like iterators to enable range-based for loop support.
void	BulkSerialize ( FArchive& Ar, bool bForcePerElementSerialization )	Bulk serialize array as a single memory blob when loading.
void	CheckAddress ( const ElementType* Addr )	Checks that the specified address is not part of an element within the container.
void	CheckInvariants()	Checks array invariants: if array size is greater than or equal to zero and less than or equal to the maximum.
bool	Contains ( const ComparisonType& Item )	Checks if this array contains the element.
bool	ContainsByPredicate ( Predicate Pred )	Checks if this array contains an element for which the predicate is true.
void	CopyUnfrozen ( const FMemoryUnfreezeContent& Cont..., void* Dst )
void	CountBytes ( FArchive& Ar )	Count bytes needed to serialize this array.
TConstIterat...	CreateConstIterator()	Creates a const iterator for the contents of this array
TIterator	CreateIterator()	Creates an iterator for the contents of this array
SizeType	Emplace ( ArgsType&&... Args )	Constructs a new item at the end of the array, possibly reallocating the whole array to fit.
ElementType ...	Emplace_GetRef ( ArgsType&&... Args )	Constructs a new item at the end of the array, possibly reallocating the whole array to fit.
void	EmplaceAt ( SizeType Index, ArgsType&&... Args )	Constructs a new item at a specified index, possibly reallocating the whole array to fit.
ElementType ...	EmplaceAt_GetRef ( SizeType Index, ArgsType&&... Args )	Constructs a new item at a specified index, possibly reallocating the whole array to fit.
void	Empty ( SizeType Slack )	Empties the array. It calls the destructors on held items if needed.
RangedForIte...	end()
RangedForCon...	end()
TArray< Elem...	FilterByPredicate ( Predicate Pred )	Filters the elements in the array based on a predicate functor.
bool	Find ( const ElementType& Item, SizeType& Index )	Finds element within the array.
SizeType	Find ( const ElementType& Item )	Finds element within the array.
ElementType ...	FindByKey ( const KeyType& Key )	Finds an item by key (assuming the ElementType overloads operator== for the comparison).
const Elemen...	FindByKey ( const KeyType& Key )	Finds an item by key (assuming the ElementType overloads operator== for the comparison).
const Elemen...	FindByPredicate ( Predicate Pred )	Finds an element which matches a predicate functor.
ElementType ...	FindByPredicate ( Predicate Pred )	Finds an element which matches a predicate functor.
bool	FindItemByClass ( SearchType** Item, SizeType* ItemIndex, SizeType StartIndex )	Searches for the first entry of the specified type, will only work with TArray.
SizeType	FindLast ( const ElementType& Item )	Finds element within the array starting from the end.
bool	FindLast ( const ElementType& Item, SizeType& Index )	Finds element within the array starting from the end.
SizeType	FindLastByPredicate ( Predicate Pred )	Searches the array for the last occurrence of an element which matches the specified predicate.
SizeType	FindLastByPredicate ( Predicate Pred, SizeType Count )	Searches an initial subrange of the array for the last occurrence of an element which matches the specified predicate.
SIZE_T	GetAllocatedSize()	Helper function to return the amount of memory allocated by this container.
ElementAlloc...	GetAllocatorInstance()
const Elemen...	GetAllocatorInstance()
ElementType ...	GetData()	Helper function for returning a typed pointer to the first array entry.
const Elemen...	GetData()	Helper function for returning a typed pointer to the first array entry.
SizeType	GetSlack()	Returns the amount of slack in this array in elements.
constexpr ui...	GetTypeSize()	Helper function returning the size of the inner type.
void	Heapify ( const PREDICATE_CLASS& Predicate )	Implicit heaps Builds an implicit heap from the array.
void	Heapify()	Builds an implicit heap from the array.
void	HeapPop ( ElementType& OutItem, bool bAllowShrinking )	Removes the top element from the heap.
void	HeapPop ( ElementType& OutItem, const PREDICATE_CLASS& Predicate, bool bAllowShrinking )	Removes the top element from the heap.
void	HeapPopDiscard ( bool bAllowShrinking )	Removes the top element from the heap.
void	HeapPopDiscard ( const PREDICATE_CLASS& Predicate, bool bAllowShrinking )	Removes the top element from the heap.
SizeType	HeapPush ( ElementType&& InItem )	Adds a new element to the heap.
SizeType	HeapPush ( const ElementType& InItem )	Adds a new element to the heap.
SizeType	HeapPush ( ElementType&& InItem, const PREDICATE_CLASS& Predicate )	Adds a new element to the heap.
SizeType	HeapPush ( const ElementType& InItem, const PREDICATE_CLASS& Predicate )	Adds a new element to the heap.
void	HeapRemoveAt ( SizeType Index, const PREDICATE_CLASS& Predicate, bool bAllowShrinking )	Removes an element from the heap.
void	HeapRemoveAt ( SizeType Index, bool bAllowShrinking )	Removes an element from the heap.
void	HeapSort ( const PREDICATE_CLASS& Predicate )	Performs heap sort on the array.
void	HeapSort()	Performs heap sort on the array.
ElementType ...	HeapTop()	Returns the top element from the heap (does not remove the element).
const Elemen...	HeapTop()	Returns the top element from the heap (does not remove the element). Const version.
SizeType	IndexOfByKey ( const KeyType& Key )	Finds an item by key (assuming the ElementType overloads operator== for the comparison).
SizeType	IndexOfByPredicate ( Predicate Pred )	Finds an item by predicate.
void	Init ( const ElementType& Element, SizeType Number )	Sets the size of the array, filling it with the given element.
SizeType	Insert ( TArray< ElementType, OtherAllocator..., const SizeType InIndex )	Inserts given elements into the array at given location.
SizeType	Insert ( const TArray< ElementType, OtherAll..., const SizeType InIndex )	Inserts given elements into the array at given location.
SizeType	Insert ( const ElementType* Ptr, SizeType Count, SizeType Index )	Inserts a raw array of elements at a particular index in the TArray.
SizeType	Insert ( TArray< typename TContainerElementT..., const SizeType InIndex )	Inserts given elements into the array at given location. Compatible element type version.
SizeType	Insert ( const TArray< typename TContainerEl..., const SizeType InIndex )	Inserts given elements into the array at given location. Compatible element type version.
SizeType	Insert ( ElementType&& Item, SizeType Index )	Inserts a given element into the array at given location. Move semantics version.
SizeType	Insert ( std::initializer_list< ElementType ..., const SizeType InIndex )	Inserts given elements into the array at given location.
SizeType	Insert ( const ElementType& Item, SizeType Index )	Inserts a given element into the array at given location.
ElementType ...	Insert_GetRef ( ElementType&& Item, SizeType Index )	Inserts a given element into the array at given location. Move semantics version.
ElementType ...	Insert_GetRef ( const ElementType& Item, SizeType Index )	Inserts a given element into the array at given location.
void	InsertDefaulted ( SizeType Index )	Inserts a given number of default-constructed elements into the array at a given location.
void	InsertDefaulted ( SizeType Index, SizeType Count )
ElementType ...	InsertDefaulted_GetRef ( SizeType Index )	Inserts a default-constructed element into the array at a given location.
void	InsertUninitialized ( SizeType Index )	Inserts a given number of uninitialized elements into the array at given location.
void	InsertUninitialized ( SizeType Index, SizeType Count )
void	InsertZeroed ( SizeType Index, SizeType Count )
void	InsertZeroed ( SizeType Index )	Inserts a given number of zeroed elements into the array at given location.
ElementType ...	InsertZeroed_GetRef ( SizeType Index )	Inserts a zeroed element into the array at given location.
bool	IsEmpty()	Returns true if the array is empty and contains no elements.
bool	IsValidIndex ( SizeType Index )	Tests if index is valid, i.e. greater than or equal to zero, and less than the number of elements in the array.
const Elemen...	Last ( SizeType IndexFromTheEnd )	Returns n-th last element from the array. Const version of the above.
ElementType ...	Last ( SizeType IndexFromTheEnd )	Returns n-th last element from the array.
SizeType	Max()	Returns maximum number of elements in array.
SizeType	Num()	Returns number of elements in array.
TEnableIf<&#...	Pop ( bool bAllowShrinking )	Pops element from the array.
void	Push ( const ElementType& Item )	Pushes element into the array. Const ref version of the above.
void	Push ( ElementType&& Item )	Pushes element into the array.
void	RangeCheck ( SizeType Index )	Checks if index is in array range.
SizeType	Remove ( const ElementType& Item )	Removes as many instances of Item as there are in the array, maintaining order but not indices.
SizeType	RemoveAll ( const PREDICATE_CLASS& Predicate )	Remove all instances that match the predicate, maintaining order but not indices Optimized to work with runs of matches/non-matches
SizeType	RemoveAllSwap ( const PREDICATE_CLASS& Predicate, bool bAllowShrinking )	Remove all instances that match the predicate
void	RemoveAt ( SizeType Index )	Removes an element (or elements) at given location, then shrinks the array.
void	RemoveAt ( SizeType Index, CountType Count, bool bAllowShrinking )	Removes an element (or elements) at given location, optionally shrinking the array.
void	RemoveAtSwap ( SizeType Index, CountType Count, bool bAllowShrinking )	Removes an element (or elements) at given location, optionally shrinking the array.
void	RemoveAtSwap ( SizeType Index )	Removes an element (or elements) at given location, then shrinks the array.
SizeType	RemoveSingle ( const ElementType& Item )	Removes the first occurrence of the specified item in the array, maintaining order but not indices.
SizeType	RemoveSingleSwap ( const ElementType& Item, bool bAllowShrinking )	Removes the first occurrence of the specified item in the array.
SizeType	RemoveSwap ( const ElementType& Item, bool bAllowShrinking )	Removes item from the array.
void	Reserve ( SizeType Number )	Reserves memory such that the array can contain at least Number elements.
void	Reset ( SizeType NewSize )	Same as empty, but doesn't change memory allocations, unless the new size is larger than the current array.
void	SetNum ( SizeType NewNum, bool bAllowShrinking )	Resizes array to given number of elements.
void	SetNumUninitialized ( SizeType NewNum, bool bAllowShrinking )	Resizes array to given number of elements. New elements will be uninitialized.
void	SetNumUnsafeInternal ( SizeType NewNum )	Does nothing except setting the new number of elements in the array.
void	SetNumZeroed ( SizeType NewNum, bool bAllowShrinking )	Resizes array to given number of elements, optionally shrinking it. New elements will be zeroed.
void	Shrink()	Shrinks the array's used memory to smallest possible to store elements currently in it.
void	Sort()	Sorts the array assuming < operator is defined for the item type.
void	Sort ( const PREDICATE_CLASS& Predicate )	Sorts the array using user define predicate class.
void	StableSort ( const PREDICATE_CLASS& Predicate )	Stable sorts the array using user defined predicate class.
void	StableSort()	Stable sorts the array assuming < operator is defined for the item type.
void	Swap ( SizeType FirstIndexToSwap, SizeType SecondIndexToSwap )	Element-wise array element swap. This version is doing more sanity checks than SwapMemory.
void	SwapMemory ( SizeType FirstIndexToSwap, SizeType SecondIndexToSwap )	Element-wise array memory swap.
const Elemen...	Top()	Returns the top element, i.e. the last one. Const version of the above.
ElementType ...	Top()	Returns the top element, i.e. the last one.
void	ToString ( const FPlatformTypeLayoutParameters..., FMemoryToStringContext& OutContext )
void	VerifyHeap ( const PREDICATE_CLASS& Predicate )	Verifies the heap.
void	WriteMemoryImage ( FMemoryImageWriter& Writer )

Operators

	Name	Description
	operator const TArray< typename TContainerElementTypeCompatibility< AliasElementType >::ReinterpretType, AllocatorType > &()	Implicit conversion operator to constant container of compatible element type.
	operator TArray< typename TContainerElementTypeCompatibility< AliasElementType >::ReinterpretType, AllocatorType > &()	Implicit conversion operator to container of compatible element type.
bool	operator!= ( const TArray& OtherArray )	Inequality operator.
ElementType ...	operator[] ( SizeType Index )	Array bracket operator. Returns reference to element at given index.
const Elemen...	operator[] ( SizeType Index )	Array bracket operator. Returns reference to element at given index. Const version of the above.
TArray &	operator+= ( TArray&& Other )	Appends the specified array to this array. Cannot append to self. Move semantics version.
TArray &	operator+= ( const TArray& Other )	Appends the specified array to this array. Cannot append to self.
TArray &	operator+= ( std::initializer_list< ElementType ... )	Appends the specified initializer list to this array.
TArray &	operator= ( std::initializer_list< InElementTyp... )	Initializer list assignment operator.
TArray &	operator= ( const TArray& Other )	Assignment operator.
TArray &	operator= ( const TArrayView< OtherElementType,... )
TArray &	operator= ( const TArray< ElementType, OtherAll... )	Assignment operator.
TArray &	operator= ( TArray&& Other )	Move assignment operator.
TArray &	operator= ( TArray< typename TContainerElementT... )	Move assignment operator. Compatible element type version.
TArray &	operator= ( const TArray< typename TContainerEl... )	Assignment operator.
TArray< InEl...	operator= ( const TArrayView< OtherElementType,... )
bool	operator== ( const TArray& OtherArray )	Equality operator.

Typedefs

Name	Description
Allocator
AllocatorType
ElementAllocatorType
ElementType
RangedForConstIteratorType
RangedForIteratorType
SizeType
TConstIterator
TIterator	Iterators.
USizeType

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