Question

This is c++ programming and here is my code. I am getting an exception thrown on the destructor for permanentworker. Can you tell me why I am getting this exception?

#include <iostream>
#pragma warning(disable:4996)

class PermanentWorker
{
private:
   char *name;
   int salary;
public:
   PermanentWorker(const char* nam, int money) : salary(money)
   {
       name = new char[strlen(nam) + 1];
       strcpy(name, nam);
   }
   int getPay() const
   {
       return salary;
   }
   void showSalaryInfo()
   {
       std::cout << "name: " << name << std::endl;
       std::cout << "salary: " << getPay() << std::endl << std::endl;
   }
   ~PermanentWorker()
   {
       delete[] name;
       std::cout << "called PermanentWorker destructor" << std::endl;
   }
};

class EmployeeHandler
{
private:
   PermanentWorker* employeeList[50];
   int employeeNumber;
public:
   EmployeeHandler() : employeeNumber(0)
   {

   }
   void addEmployee(PermanentWorker* employee)
   {
       employeeList[employeeNumber++] = employee;
   }
   void showAllSalaryInfo() const
   {
       for (int i = 0; i < employeeNumber; i++)
       {
           employeeList[i]->showSalaryInfo();
       }
   }
   void showTotalSalary() const
   {
       int sum = 0;
       for (int i = 0; i < employeeNumber; i++)
       {
           sum += employeeList[i]->getPay();
       }
       std::cout << "salary sum: " << sum << std::endl;
   }
   ~EmployeeHandler()
   {
       for (int i = 0; i < employeeNumber; i++)
       {
           delete[] employeeList[i];
       }
   }
};

int main()
{
   EmployeeHandler handler;

   handler.addEmployee(new PermanentWorker("Dean", 3000));
   handler.addEmployee(new PermanentWorker("Joyce", 4000));
   handler.addEmployee(new PermanentWorker("Sunny", 2000));

   handler.showAllSalaryInfo();

   handler.showTotalSalary();
   return 0;
}

Answer 1

Done

Mistake is you first deleted whole pointer of PermanentWorker and again calling destructor which access freed memory so error raises

Now its clear see the output

#include <iostream>
#include<cstring>
#pragma warning(disable:4996)
class PermanentWorker
{
private:
   char *name;
   int salary;
public:
   PermanentWorker(const char* nam, int money) : salary(money)
   {
       name = new char[strlen(nam) + 1];
       strcpy(name, nam);
   }
   char * getname(){
       return name;
   }
   int getPay() const
   {
       return salary;
   }
   void showSalaryInfo()
   {
       std::cout << "name: " << name << std::endl;
       std::cout << "salary: " << getPay() << std::endl << std::endl;
   }
   ~PermanentWorker()
   {
       delete []name;
     
       std::cout << "called PermanentWorker destructor" << std::endl;
   }
};

class EmployeeHandler
{
private:
   PermanentWorker* employeeList[50];
   int employeeNumber;
public:
   EmployeeHandler() : employeeNumber(0)
   {

   }
   void addEmployee(PermanentWorker* employee)
   {
       employeeList[employeeNumber++] = employee;
   }
   void showAllSalaryInfo() const
   {
       for (int i = 0; i < employeeNumber; i++)
       {
           employeeList[i]->showSalaryInfo();
       }
   }
   void showTotalSalary() const
   {
       int sum = 0;
       for (int i = 0; i < employeeNumber; i++)
       {
           sum += employeeList[i]->getPay();
       }
       std::cout << "salary sum: " << sum << std::endl;
   }
   ~EmployeeHandler()
   {
           for(int i=0;i<employeeNumber;i++){
               delete employeeList[i];
        }
   }
};

int main()
{
   EmployeeHandler handler;

   handler.addEmployee(new PermanentWorker("Dean", 3000));
   handler.addEmployee(new PermanentWorker("Joyce", 4000));
   handler.addEmployee(new PermanentWorker("Sunny", 2000));

   handler.showAllSalaryInfo();

   handler.showTotalSalary();
   return 0;

}

name: Dean salary: 3000 name: Joyce salary: 4000 name: Sunny salary: 2000 salary sum: 9000 called PermanentWorker destructor called PermanentWorker destructor called Permanentworker destructor