C/C++ Copy Assignment Operator for CarCounter Class

[kstewa17]

Write a copy assignment operator for CarCounter that assigns objToCopy.carCount to the new objects's carCount, then returns *this. Sample output for the given program:

Cars counted: 12

#include <iostream>
using namespace std;

class CarCounter {
   public:
      CarCounter();
      CarCounter& operator=(const CarCounter& objToCopy);
      void SetCarCount(const int setVal) {
         carCount = setVal;
      }
      int GetCarCount() const {
         return carCount;
      }
   private:
      int carCount;
};

CarCounter::CarCounter() {
   carCount = 0;
   return;
}

// FIXME write copy assignment operator

/* Your solution goes here  */

[B]CarCounter& CarCounter::operator=(const CarCounter& objToCopy) {
  
   
   if (this != &objToCopy) {           
      delete setVal;                  
      setVal = new int;               
      *setVal = *(objToCopy.dataObj); 
   }
   
   return *this;[/B]

int main() {
   CarCounter frontParkingLot;
   CarCounter backParkingLot;

   frontParkingLot.SetCarCount(12);
   backParkingLot = frontParkingLot;

   cout << "Cars counted: " << backParkingLot.GetCarCount();

   return 0;
}

 

[johng1]

Re: C/C++ (Copy Assignment)...What I have so far is is red, and it's confusing me a little.

CarCounter& CarCounter::operator=(const CarCounter& objToCopy) {
   if (this != &objToCopy) {
      delete setVal;
      setVal = new int;
      *setVal = *(objToCopy.dataObj);
   }
   return *this;

}

First, this post belongs in the computer science section. Your code is missing
a closing } so it can't compile. Furthermore, there is no field of CarCounter
that is named setval. Again compiler error. Apparently, you tried to mimic a
correct assignment operator for a different class. Your main setup is correct
but the details are all wrong.

An assignment operator = is meant to assign an exact copy of ObjToCopy to
the object on the left side of the =. So, for example, if you have two objects
car1 and car2 of class CarCounter, car1=car2 should have the effect of making
car1 an exact copy of car2.

Here's a correct assignment operator:

const CarCounter& CarCounter::operator=(const CarCounter& objToCopy) {
   if (this != &objToCopy) {
      carCount = objToCopy.getCarCount();
   }
   return *this;
  }

}

"Most" people want the assignment operator to return a const reference to
an object of the class, but there is some disagreement about this.