Resolving UE5 UE4497 Warning: Member Variable Not Initialized in Constructor

Why You’re Seeing This Error

This UE5-specific warning occurs when you have a member variable in your class that isn’t being initialized in any constructor. Uninitialized variables can lead to unpredictable behavior.

Example Error Message

warning UE4497: 'MyActor.h(45): Member variable 'DamageAmount' is not initialized in constructor 'AMyActor::AMyActor()'.

Solution

1. Initialize the variable in the constructor: Add initialization in your constructor.

// In MyActor.h
UPROPERTY(EditAnywhere, Category = "Combat")
float DamageAmount;

// In MyActor.cpp
AMyActor::AMyActor()
{
    PrimaryActorTick.bCanEverTick = true;
    
    // Initialize member variable
    DamageAmount = 10.0f;
}

2. Initialize directly in the class declaration:

UPROPERTY(EditAnywhere, Category = "Combat")
float DamageAmount = 10.0f;  // In-place initialization

3. Use member initializer lists:

AMyActor::AMyActor()
    : DamageAmount(10.0f)
    , Health(100.0f)
{
    PrimaryActorTick.bCanEverTick = true;
}

4. Suppress the warning if appropriate: If you’re initializing the variable elsewhere (like in BeginPlay), you can suppress the warning.

UPROPERTY(EditAnywhere, Category = "Combat")
float DamageAmount;  // Will be initialized in BeginPlay

// In cpp file
void AMyActor::BeginPlay()
{
    Super::BeginPlay();
    DamageAmount = GetDefaultDamage();  // Dynamic initialization
}