一.先来看官方文档如何描述，写的通俗易懂。直接些测试代码

Append 能一次加多个，注意可能要换成UE_ARRAY_COUNT 算要加的数组的大小。

AddUnique()只会添加没有的，独一无二的。

Insert 插到指定下标。0,1,2,3

SetNum设置容器元素数量，没有的用元素类型默认构造，多的就移除。

二.测试代码

UCLASS()
class NETPRACTICE_API AWXTArrayActor : public AActor
{
	GENERATED_BODY()
	
public:	
	UFUNCTION(BlueprintCallable)
	void AddStructArray();

	UFUNCTION(BlueprintCallable)
	void EmplaceArray();

	UFUNCTION(BlueprintCallable)
	TArray<FString> AppendStrArray();

	UFUNCTION(BlueprintCallable)
	void AddUniqueString();

	UFUNCTION(BlueprintCallable)
	void InsertString();

	UFUNCTION(BlueprintCallable)
	void SetStringNum();

	// Sets default values for this actor's properties
	AWXTArrayActor();

protected:
	// Called when the game starts or when spawned
	virtual void BeginPlay() override;

public:	
	// Called every frame
	virtual void Tick(float DeltaTime) override;

	UPROPERTY()
	TArray<FXGAddStructInfo> StructArray;

};

void AWXTArrayActor::AddStructArray()
{
	StructArray.Add(100);
}

void AWXTArrayActor::EmplaceArray()
{
	StructArray.Emplace(200);
}

TArray<FString> AWXTArrayActor::AppendStrArray()
{
	FString Arr[] = {TEXT("of"),TEXT("Futrue")};
	TArray<FString> StrArr;
	StrArr.Add(TEXT("Hello"));
	StrArr.Emplace(TEXT("World"));
	StrArr.Append(Arr,UE_ARRAY_COUNT(Arr));
	return StrArr;
}

void AWXTArrayActor::AddUniqueString()
{
	TArray<FString> StrArr = AppendStrArray();
	StrArr.AddUnique(TEXT("!"));
	StrArr.AddUnique(TEXT("!"));
}

void AWXTArrayActor::InsertString()
{
	TArray<FString> StrArr = { "Hello","Baby","Fuck" };
	StrArr.Insert(TEXT("What"),2);
}

void AWXTArrayActor::SetStringNum()
{
	TArray<FString> StrArr = { "Hello","Baby","Fuck" };
	StrArr.SetNum(10);
	StrArr.SetNum(5);
}

在蓝图中测试，去编辑器代码。查看