Question

Lets say in my main method, I declare a const int array pointer pointing to an array created on the heap. I then want to initialize it’s values (using the memory address) in a constructor TryInitialize() and then print them out. This is not working and I’m wondering what I’m doing wrong? Thanks!

#include "stdafx.h"
#include "part_one.h"
#include <string>
#include <iostream>

using namespace std;

string createTable(unsigned int* acc, double* bal, int n) {
    string s;
    char buf[50];

    for (int i = 0; i < n; i++) {
            sprintf_s(buf,"%7u\t%10.2f\n",acc[i], bal[i]);
            s += string(buf);
    }

    return s;
}



int _tmain(int argc, _TCHAR* argv[])
{

    const int *tempInt = new const int[4];
    TryInitialize(tempInt);
    std::cout << tempInt[1] << endl;

    system("pause");

    return 0;
}

And here is my code for my constructor:

#include "part_one.h"


TryInitialize::TryInitialize(void) {

}

TryInitialize::TryInitialize(int constInt[]) {
    constInt[0] = 8;
    constInt[1] = 0;
    constInt[2] = 0;
    constInt[3] = 8;
}

Answer 1

You should not change a const value.

For what you trying to accomplish I’d recommend declaring a non-const pointer and a const pointer and assigning the non-const one to the const one after the initialization:

int _tmain(int argc, _TCHAR* argv[])
{
    const int *tempTempInt = new int[4];
    TryInitialize(tempInt);
    const int* const tempInt = tempTempInt;
    std::cout << tempInt[1] << endl; //this is now constant.

    system("pause");

    return 0;
}

Also pay attention where you put the const in the pointer declaration:

const int* const tempInt = tempTempInt;

In the declaration above the second const means that you cannot change the pointer; the first const means that you cannot change the pointed value(s).