Passing an object by reference to function doesnt change this object

Question

so basically, I'm trying to pass an object to my function Attack():

void Character::Attack(Character &another, short int range)
{
    if (EnemyInRange(range) && another.health > 0)
    {
        if (allowed_to_attack)
        {
            attacked = true;

            cout << name << " attacked " << another.name << " taking " << attack << " damage" << endl;


            if (another.defensive > 0) // less important things down there
            {
                another.defensive--;

                if (attack > another.defensive)
                {
                    another.health -= (attack - another.defensive);
                }
            }
            else if (another.defensive == 0)
            {
                another.health -= attack;
            }


            if (another.defensive <= 0)
                another.defensive = 0;

            if (another.health <= 0)
            {
                another.health = 0;
                another.draw = false;
                another.~Character();
            }

        }

        else
        {
            attacked = false;
            cout << "Blocked" << endl;
        }

    }
    else
        cout << name << " wanted to attack " << another.name << " ,but he's out of the range" << endl;

As you see, I'm using reference to pass an object. BUT, when I call this function:

void onClick(Vector2f mouse_position, Character current, Character *& target, Position &positionx)
{
    for (int i = 0; i < 4; i++)
    {
        for (int j = 0; j < 5; j++)
        {
            if ((mouse_position.x >= 245 + i * 164 && mouse_position.x <= 370 + i * 164) &&
                (mouse_position.y >= 56 + j * 201 && mouse_position.y <= 221 + j * 201))
            { // there's a 2d map with cards on those positions
                target = &positionx.positioning[i][j];
                current.Attack(*target);
            }
        }
    }

}

positioning is an array filled with characters

It's behaving like I passed a copy of an object target (it writes out name, but it doesn't change its health)

in main() it looks like this:

Character *current = new Character();
Character *target = NULL;

if ((event.type == Event::MouseButtonPressed) && (event.mouseButton.button == Mouse::Left))//SFML lib
{
    Vector2i pos = Mouse::getPosition(window);
    Vector2f position = (Vector2f)pos;
    onClick(position, *current, target, positionx);
} // target is selected after clicking on it

Why do you manually call the destructor another.~Character(); and what does this destructor do? This may cause strange behavior and there is almost no reason to manually call a destructor. — Lukas-T
– Lukas-T, Commented Apr 27, 2020 at 16:20
I wanted to make sure, that if character's health drops to 0, it will get destroyed — Bartasus1
– Bartasus1, Commented Apr 27, 2020 at 16:33

Azam Bham · Accepted Answer · 2020-04-27 16:09:41Z

1

In the function onClick, the variable current is passed by value not reference. I assume that is supposed to be passed by reference:

void onClick(Vector2f mouse_position, Character &current, Character *target, Position &positionx)

Notice the argument current has been updated to a reference.

Edit:

Looking at the body of the Attack function, if the line printing out the name is met, are you sure the if-conditional statements if(another.defensive > 0) and if(attack > another.defensive) are met?

edited Apr 27, 2020 at 16:09

answered Apr 27, 2020 at 15:36

Azam Bham

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3 Comments

SKCoder Over a year ago

Isn't the question about "target"? As far as I see "current" modifies "target", or at least should modify it.

Bartasus1 Over a year ago

SKCoder is right. I wanted to make " *target " modified, and "current" is object that runs "Attack()" method. I changed current to reference, but its still not working

Bartasus1 Over a year ago

@Azam Every thing was working fine when i was using Attack outside onClick function.

Bartasus1 · Accepted Answer · 2020-04-27 16:49:27Z

0

Do you think that Position &positionx might be a problem here? The most important part of onClick() function is target = &positionx.positioning[i][j]. But its passed by reference, so it shouldnt make a problem.

answered Apr 27, 2020 at 16:49

Bartasus1

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