De-allocating memory within loops

Question

I was reading through MIT's Introduction to C++ and one code example showed:

int *getPtrToFive() {
    int *x = new int;
    *x = 5;
    return x;
}

int main() {
    int *p;
    for (int i = 0; i < 3; ++i) {
        p = getPtrToFive();
        cout << *p << endl;
        delete p;
    }
}

I was wondering why it is possible to delete "p" after every iteration despite "p" being declared once before the loop started and was not allocated using "new".

Another question is when "*x" is assigned the value 5 in the function, since it is a pointer the memory address would be changed right? So it would be something like 0x00005 instead of the actual value 5?

Answer 1

I was wondering why it is possible to delete "p" after every iteration despite "p" being declared once before the loop started and was not allocated using "new"

No. You are not deleting p, you are deleting the object p points to, which is allocated using new each iteration.

Another question is when "*x" is assigned the value 5 in the function, since it is a pointer the memory address would be changed right? So it would be something like 0x00005 instead of the actual value 5?

The value of x would be something like 0xFFd00whatever. but you are printing the value of *x, which is "the number that is in the memory at address 0xFFd00whatever". There is no x=5 in your code; there's only *x=5. It means "go to the address to which x points to, and put the number 5 in there".

You can think about it this way: you have a hand, okay? let's call it "x". The command

x = new int;

Means "point your finger at some empty place on your desk." Where

*x = 5;

Means "draw the number five where your hand points to".