Beginning C++ Through Gam…rogramming (2nd Edition)/BCGP2E.ISO/source/chapter07/inventory_pointer.cpp

C/C++ Source or Header | 2004-04-11 | 2KB | 51 lines

// Inventory Pointer
// Demonstrates returning a pointer

#include <iostream>
#include <string>
#include <vector>

using namespace std;

//returns a pointer to a string element
string* ptrToElement(vector<string>* const pVec, int i);

int main()
{
    vector<string> inventory;
    inventory.push_back("sword");
    inventory.push_back("armor");
    inventory.push_back("shield");

    //displays string object that the returned pointer points to
    cout << "Sending the objected pointed to by returned pointer:\n";
    cout << *(ptrToElement(&inventory, 0)) << "\n\n";

    //assigns one pointer to another -- inexpensive assignment
    cout << "Assigning the returned pointer to another pointer.\n";
    string* pStr = ptrToElement(&inventory, 1);
    cout << "Sending the object pointed to by new pointer to cout:\n";
    cout << *pStr << "\n\n";

    //copies a string object -- expensive assignment
    cout << "Assigning object pointed by pointer to a string object.\n";
    string str = *(ptrToElement(&inventory, 2));
    cout << "Sending the new string object to cout:\n";
    cout << str << "\n\n";

    //altering the string object through a returned pointer
    cout << "Altering an object through a returned pointer.\n";
    *pStr = "Healing Potion";
    cout << "Sending the altered object to cout:\n";
    cout << inventory[1] << endl;

    return 0;
}

string* ptrToElement(vector<string>* const pVec, int i)
{
    //returns address of the string in position i of vector that pVec points to
    return &((*pVec)[i]);
}