Question

#include <stdio.h>
#include <iostream>
#include <string>


using namespace std;

class myClass{

public:
    int *num1;
    myClass();


};

myClass::myClass(){
    num1 = new int[1];
    num1[0] = 10;
}


int main()
{
    myClass *myclass;

    myclass = new myClass[10];

    cout << myclass[0].num1[0] << endl;

    delete &myclass[0];
    cout << myclass[0].num1[0] << endl;

}

I want to delete the first instance of myclass (myclass[0]).

This code does not run correctly, it fails during the delete part. There is probably something I am missing.

What did I do wrong?

Answer 1

Create a function inside of your class the handles the deletion of its private members, maybe called FreeMem(int index)

void myClass::FreeMem()
{
    delete [] num1
}

But honestly, freeing memory of an object without the use of a destructor in this sort of a program is hazardous and downright bad practice. I would recommend freeing the memory in your destructor, so when the object terminates it frees the memory,

myClass::~myClass()
{
    delete [] num1;
}

Another thing to note on, if you’re only creating one value in your dynamic variable, it would be easier to write it as:

int * pnum = new int;
//or in your class..
pnum = new int;

among other things, you have a lot of flaws in your program. I would recommend re-reading up on classes again.