Ways to get GameInstance in Unreal Engine C++

There are several ways to get the GameInstance, and for the most part it depends on where you want to get this object from.

In the examples below, "UGameInstanceCreated" is a C++ generated GameInstance class.

If you have UWorld:

UGameInstanceCreated* GameInstanceRef = Cast<UGameInstanceCreated>(UGameplayStatics::GetGameInstance(GetWorld())

If you don't have UWorld:

UGameInstanceCreated* GameInstanceRef = Cast<UGameInstanceCreated>(GEngine->GetWorld()->GetGameInstance());

If you are unsure of a specific method, there is an option for testing to understand that at least one of the ways to get GameInstance works:

if (GetWorld() != nullptr && GetWorld()->GetGameInstance() != nullptr)
{
	UGameInstanceCreated* GameInstanceRef = Cast<UGameInstanceCreated>(UGameplayStatics::GetGameInstance(GetWorld())
}
else if (GetGameInstance())
{
	UGameInstanceCreated* GameInstanceRef = Cast<UGameInstanceCreated>(GEngine->GetWorld()->GetGameInstance());
}else
{
	UE_LOG(LogTemp, Error, TEXT("Game Instance cannot be obtained") );
}