Having trouble with enum syntax

Development Programming & Scripting
1

I’m trying to create a new enum to keep track of the player’s current state, and I’m having trouble with the definition:

UCLASS( ClassGroup=(Custom), meta=(BlueprintSpawnableComponent) )
class LEARNINGPROJECT_API ULexicon : public UActorComponent
{
	GENERATED_BODY()

public:	

	// Called when the game starts
	virtual void BeginPlay() override;
	
	// Called every frame
	virtual void TickComponent( float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction ) override;	
};

UENUM()
enum class ECharacterState : uint8{
	Locomotion
	Attacking
	Grabbing
	Dodging
};

This produces boatloads of syntax errors on compile, so I assume I’m doing something slightly wrong, but it looks identical to my example in A new, community-hosted Unreal Engine Wiki - Announcements - Unreal Engine Forums , the only difference is the lack of BlueprintType in the UENUM(), which is unnecessary since I’m only using this enum in code.

2

You need a comma to separate entries in the enum.

UENUM()
 enum class ECharacterState : uint8{
     Locomotion,
     Attacking,
     Grabbing,
     Dodging,
 };
3

Oh hey, that fixes everything, thank you!!

I’m curious, what’s the purpose of the uint8 designation to the right of the enum’s name? Is that just specifying how it’s hashed or something?

4

The type to the right of the enum class declaration defines how large the enum type should be.

The Unreal Header Tool (UHT) only supports enums that are 1-byte, so the uint8 designation ensures that your enum is 1-byte. Prior to C++11 and UHT support for enum class, we used to enforce this by using TEnumAsByte when declaring enum properties - you may still see this in existing engine code.

5

That’s super-helpful, thank you very much for the clarification :slight_smile: