Thread: Pointer Question

Hey I am currently teaching myself C++ programming and I have a question about when I need to delete pointers to free up memory. I have been going through the examples in my book I believe I somewhat understand what pointers are used for and also have read that eventually I will know better when I should use them though I am wondering do you always have to delete a pointer before the program ends? The examples I have been doing always delete the pointer at the very end of the program and I was wondering is this actually something needed to be done so the pointer does not eat up memory even after the program is done running or is it just something that is done in the examples to help get people into the habit of deleting their pointers?

This is one of the examples that I am talk about how it has the "delete ps;" right at the end.

Code:

// newstrct.cpp -- using new with a structure
#include <iostream>


struct inflatable   //definition of structure
{
    char name[20];
    float volume;
    double price;
};


int main()
{
    using namespace std;
    inflatable *ps = new inflatable;    //allot memory for structure
    cout<< " Etner name of inflatable item: ";
    cin.get(ps->name, 20);              //method 1 for member access
    cout<< "Enter volume in cubic feet: ";
    cin >> (*ps).volume;                //method 2 for member access
    cout<< "enter price: $";
    cin >> ps -> price;
    cout<< "Name: " << (*ps).name << endl;      //method 2
    cout<< "Volume: " << ps->volume << " cubic feet\n"; //method 1
    cout<< "Price: $" << ps ->price << endl;            //method 1
    delete ps;                                  //free memory used by structure
    return 0;
}

If anyone is able to answer or even just give me advice on pointers in general it would be fairly helpful because out of all of the topics I have learned about so far I understand pointers the least.

Strictly speaking, no you don't need to delete a pointer allocated through new when a program ends, as a modern OS will clean up after your memory leak. However, it is a good (and standard) practice to always delete dynamically allocated memory. To quote Nike: Just Do It. Start off on the right foot by developing good habits.

Note that (in my experience) in the real world you will rarely, if ever, see this notation for accessing a struct element through a pointer:

Code:

(*ps).name

it will nearly always be

Code:

ps->name

The former is mainly shown as an academic exercise.

Thanks everyone for the response, I was mostly worried that I could do something wrong with pointers and completely screw up my computer if I didnt delete them on accident. I also know that some of the things in code is not how they are commonly used or not the most optimal way to do it but the aurthor did mention how ps->volume is the more widely used method. For the char array he has I believe he was showing how an array is similar to a pointer.