/UE5-CPP-TLDR

Common Specifiers

  • UCLASS Specifiers - Docs

    UCLASS(Blueprintable)

  • USTRUCT Specifiers - Docs

    #include "Grid.generated.h"

    USTRUCT(BlueprintType)
    struct FGrid
{
    GENERATED BODY()

    FORCELINE FGrid();
    explicit FORCEINLINE FGrid(int32 Value);
    explicit FORCE INLINE FGrid (In32 X, Int32 Y);

    //... add properties here
    //... No UFUNCTIONS allowed but can use non-blueprintable functions
};
  • UENUM Specifiers - Docs
    UENUM(BlueprintType) enum class Foo : Uint8
    {
        None = 0 UMETA(DisplayName = "None")...
    }

  • UPROPERTY Specifiers - Docs

    UPROPERTY(VisibleAnywhere, Category = "Foo")

    UPROPERTY(BlueprintReadOnly, Category = "Foo")

    UPROPERTY(BlueprintReadWrite, Category = "Foo")

Enumerators

  • Access Display Name of UENUM in Unreal: UEnum::GetValueAsString(BuildingName);

Unreal Specific Coding Hints

  • Use TObjectPtr<ClassName> intead of raw * pointers for UPROPERTIES
  • Initialize FStrings with FString Name = TEXT("This is a a string"); to ensure platform specific encoding
  • Use check(pointer) if you want the game to stop and assert on a null pointer (if that pointer is NOT supposed to be null). Otherwise a non-breaking way is to use if (IsValid(pointer)){//... do something} - Docs

CPP Coding Hints

  • Forward declare in the .h and include in the .cpp to speed up compile times and limit cross reference errors
  • Initialize variables using the initilazation methode so use int32 X{5}; instead of int32 X = 5;
  • Use bitfields for booleans uint8 bIsFoo:1 if there are lots of booleans in a class/struct but then you cannot initialize without c++ 20 (not supported in Unreal)

Debug Printing

if (GEngine) GEngine->AddOnScreenDebugMessage(-1, 1.0f, FColor::Yellow, TEXT("Write simple message here"));
if (GEngine) GEngine->AddOnScreenDebugMessage(-1, 1.0f, FColor::Yellow, FString::Printf(TEXT("Write message with vars: %d"), IntegerVar));
UE_LOG(LogTemp, Warning, TEXT("Text: %s"), *(ID.ToString()));

Error Messages

  • Customize error category in project.h file in Source twin h

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