TArray::Num

function Core Since unknown

#include "Containers/Array.h"

Access: public Specifiers: const

Description

Returns the number of elements currently in the array. Does not include any reserved but unused capacity.

Signature

UE_FORCEINLINE_HINT SizeType Num() const

Return Type

int32

Caveats & Gotchas

• Returns int32 (SizeType), not size_t. Comparisons with size_t values (e.g. from STL containers) may produce signed/unsigned mismatch warnings.
• Use IsEmpty() rather than Num() == 0 for clarity. Both are O(1).
• Num() reflects the logical size, not the allocated capacity. Use GetSlack() to see how many elements can be added before reallocation.

Example

Loop with index and bounds-guard C++

// Iterate with index
for (int32 i = 0; i < MyArray.Num(); ++i)
{
	ProcessItem(MyArray[i]);
}

// Guard before accessing last element
if (MyArray.Num() > 0)
{
	AActor* Last = MyArray[MyArray.Num() - 1];
}

Version History

Introduced in: unknown

Version	Status	Notes
5.6	stable	—

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