Destroyer gets called right after constructor [closed] - c++

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i saw a few posts with same problem but i didn't not manage to understand how do i make the temporary object to constant
Map.H
#ifndef _Map_
#define _Map_
class Map
{
private:
int Board[7][7];
public:
Map();
Map(int mapNum);
~Map();
void print() const;
};
#endif
Map.Cpp basicly just creates a 7*7 array with 0 or 1 in all places
Robots.H
#ifndef _Robot_
#define _Robot_
#include "Map.h"
class Robot
{
private:
int _RobotID;
int _mapNum;
int _X;
int _Y;
public:
Robot();
~Robot();
Robot (int mapNum, int Line, int Column);
void setRobotID(int newid);
void print() const;
};
#endif
s
Robot.cpp
#include "Robot.h"
#include "Map.h"
#include <iostream>
#include "Game.h"
using namespace std;
Robot::Robot()
{
}
Robot::Robot(int mapNum, int line, int column) {
_mapNum = mapNum;
_X = line;
_Y = column;
_RobotID=0;
}
now creating a map in my main works and so does printing it.
same goes for robot.
what i want to do is connect the robot and the map inside my "game.cpp\game.h" so that each robot that i add will check in the map (double array with 0's or 1's )if it has a 1 it wont add it to map. and if it has a 0 it will.
(addRobot function is suppose to do that)
Game.H
#ifndef _Game_
#define _Game_
#include <vector>
#include <iostream>
#include "Map.h"
#include "Robot.h"
class Game
{
private:
static int _RobotsNum;
Map map1;
Map map2;
public:
void AddRobot(int mapnum, int x, int y);
Map getMap(int mapnum);
Game();
~Game();
};
#endif
Game cpp
#include "Game.h"
#include <algorithm>
#include <vector>
using namespace std;
int Game::_RobotsNum = 0;
vector <Robot> RobotVec;
Game::Game()
: map1(1),
map2(2)
{
}
Game::~Game()
{
}
void Game::AddRobot(int mapnum, int x, int y) {
my main
int main() {
Game game;
// Game* pgame = new Game();
game.AddRobot(1, 3, 4);
game.AddRobot(1, 4, 4);
game.AddRobot(1, 5, 4);
hope you guys can help me. thanks

Answer 1

This constructor has three local variables with the same names as other variables:
Game::Game()
{
vector <Robot> RobotVec; // Not your global variable
Map map1(1); // Not your member variable
Map map2(2); // Not your member variable either
}
In order to initialise members, you use the initialiser list:
Game::Game()
: map1(1),
map2(2)
{
}
In addRobot, this creates a robot and points X at it:
Robot* X = new Robot;
This also creates a robot, so now you have two:
Robot newRobot(mapnum, x, y);
And this memory leak points X away from its original robot and instead points it at newRobot, which will be destroyed immediately afterwards:
X = &newRobot;
Note that addRobot does not at any point add either robot to anything – it creates two and ignores them both.
You should make the vector a member (avoid global variables unless repeating other people's mistakes is a particular passion of yours):
class Game
{
private:
int robotsNum;
vector<Robot> robotVec;
Map map1;
Map map2;
// ...
};
Game::Game()
: robotsNum(0),
map1(1),
map2(2)
{
}
And add your new robot to the vector:
void Game::AddRobot(int mapnum, int x, int y) {
// ...
Robot newRobot(mapnum, x, y);
robotsNum++;
newRobot.setRobotID(robotsNum);
robotVec.push_back(newRobot);
}

Answer 2

Robot newRobot(mapnum, x, y);
This creates an object of type Robot named newRobot. At the end of the block where it was created it will be destroyed.