In C++ when we create object the constructor initializes, but if I want to reinitialize the object again, say at some point in main, what to do?

Question

For example I Have this example code:

class Player
{
   int grid;
   Player()
   {
      grid = 0;
   }

}
void main()
{
   Player p;
   ...
   ...
   //now again I want to initialize p here, what to write ?
}

How do I call the constructor of p again ?

because, if you are making a game, and the player wants to play again then all objects have to be re - initialized, does it make sense ? — Anubha, Aug 09 '12 at 13:38
Then you go back again: `while(!done){ Player p; p.Play(); }` — Bo Persson, Aug 09 '12 at 13:42
@BoPersson Is it right to create the object p again and again ? — Anubha, Aug 09 '12 at 14:09
If you want a new initialized object each time, then just create one. That's the easiest way. — Bo Persson, Aug 09 '12 at 14:13

score 5 · Answer 1 · answered Aug 09 '12 at 13:46

5

Put the object into a local scope:

while (running)
{
    Player p;  // fresh

    //...
}

Each time the loop body executes, a new Player object is instantiated.

answered Aug 09 '12 at 13:46

Kerrek SB

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@user183177: that's C++ for you -- you know that it's right when it feels best. – Kerrek SB Aug 09 '12 at 14:25

score 4 · Answer 2 · answered Aug 09 '12 at 13:40

4

class Player
{
   int grid;
   Player()
   {
      grid = 0;
   }

}
void main()
{
   Player p;
   ...
   ...
   //now again I want to initialize p here, what to write ?
   p = Player();
}

answered Aug 09 '12 at 13:40

user1052842

121
1
11

2

Although, to make this work correctly, you may have to implement the assignment operator (which isn't always simple or desirable). Often the simplest and most efficient thing is just to destroy the old object and allocate a new one. – Matteo Italia Aug 09 '12 at 13:43
That constructor is very poor practice (as is `void main`). You should really be using initializer lists. – Kerrek SB Aug 09 '12 at 14:48

score 3 · Accepted Answer · answered Aug 09 '12 at 13:34

3

Add init function. Call it in constructor, but also make it public, so you can call it later again.

Actually you can make any function you want to change the state:

class Player
{
public:
    void setState(/*anything you want*/) {}
};

answered Aug 09 '12 at 13:34

Andrew

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I think you are right, just thinking if the constructor cant be called again, instead of making a different function again... – Anubha Aug 09 '12 at 13:38

score 0 · Answer 4 · answered Aug 10 '12 at 15:42

Reinforcing Andrew's answer:

class Player
{
public:
    Player()
    {
        reset(); //set initial values to the object
    }

    //Must set initial values to all relevant fields        
    void reset()
    {
        m_grid = 0; //inital value of "m_grid"
    }

private:
    int m_grid;
}


int main()
{
    Player p1;
    Player* p2 = new Player();

    ...
    ...
    p1.reset(); 
    p2->reset(); //Reset my instance without create a new one.
}

In C++ when we create object the constructor initializes, but if I want to reinitialize the object again, say at some point in main, what to do?

4 Answers4

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