Description
Appends Count new elements at the end of the array, each default-constructed via DefaultConstructItems. Returns the index of the first added element. Unlike AddZeroed, this properly invokes the element's default constructor.
Caveats & Gotchas
- • For trivially-constructible types (int32, float, plain structs with no constructor), DefaultConstructItems falls back to zeroing, so AddDefaulted and AddZeroed behave identically for those. The difference only matters for types with a non-trivial default constructor.
- • The returned index is only valid until the next operation that might reallocate the array. Do not store it across Add/Insert/Reserve calls unless you also store GetData().
Signature
SizeType AddDefaulted(SizeType Count)Parameters
| Name | Type | Description | Default |
|---|---|---|---|
| Count | SizeType | The number of default-constructed elements to add. Omit or pass 1 for the single-element overload. | — |
Return Type
SizeType Example
Grow a TArray of FTimerHandle with proper construction C++
TArray<FTimerHandle> Timers;
int32 FirstIdx = Timers.AddDefaulted(4); // 4 properly-constructed FTimerHandles
for (int32 i = 0; i < 4; ++i)
{
GetWorldTimerManager().SetTimer(Timers[FirstIdx + i], this, &AMyActor::OnTimer, 1.f, true);
}Tags
Version History
Introduced in: 4.14
| Version | Status | Notes |
|---|---|---|
| 5.6 | stable | — |
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