Line wont execute

Development Programming & Scripting
1

I have this piece of code:

for (FTankSpawn tankSpawn : tankSpawns)
		{
			if (tankSpawn.getLocation() == spawnLocation)
			{
				tankSpawn.setDestroyed(true);
			}
		}

Where tankSpawns is:

TArray<FTankSpawn> tankSpawns;

FTankSpawn is just a struct :

USTRUCT(BlueprintType)
struct FTankSpawn
{
	GENERATED_BODY()

private:

	UPROPERTY()
		bool destroyed;
	
public:

	void setDestroyed(bool destroyed) { this->destroyed = destroyed; }

	FTankSpawn()
	{
		destroyed = false;
	}
};

When it goes inside the if statement, it never executes the line but always skips it. I have no clue why this would happen. When i put “addOnScreenDebugMessage” at the line before the function call, inside the if statement, it will execute. Next it still skips the line …setDestroyed(true)
Any ideas?

2

I think you may have defeated the iterator functionality within TArray.

Try:

for(auto&& tankSpawn : tankSpawns)
3

The problem is your undestanding of C++.
The line

for (FTankSpawn tankSpawn : tankSpawns)

Actually creates a copy of each FTankSpawn. So when you call

tankSpawn.setDestroyed(true);

You’re modifying a copy and not the actual struct.

What you should do is using and index to get your struct :

for (int i = 0; i < tankSpawns.Num(); ++i)
{
    if (tankSpawns[i].getLocation() == spawnLocation)
    {
        tankSpawns[i].setDestroyed(true);
    }
}

Or use a reference with your range-based loop:

for (FTankSpawn& tankSpawn : tankSpawns)
{
    if (tankSpawn .getLocation() == spawnLocation)
    {
        tankSpawn.setDestroyed(true);
    }
}
4

The examples at the bottom of this link make it clear what the issue is. You need to access by reference, not by value:

CPP Reference - Ranged For Loops