We can represent the player's backpack as a simple TMap<FString, int> item. To allow your player to gather items from the world, open the Avatar.h file and add the following TMap declaration:
class APickupItem; // forward declare the APickupItem class,
// since it will be "mentioned" in a member function decl below
UCLASS()
class GOLDENEGG_API AAvatar : public ACharacter
{
GENERATED_UCLASS_BODY()
// A map for the player's backpack
TMap<FString, int> Backpack;
// The icons for the items in the backpack, lookup by string
TMap<FString, UTexture2D*> Icons;
// A flag alerting us the UI is showing
bool inventoryShowing;
// member function for letting the avatar have an item
void Pickup( APickupItem *item );
// ... rest of Avatar.h same as before
};