Question

I want to write a method which takes two pointers to ints and changes the values they point to. Something like:

int main() {
    int a = 3;
    int b = 1;
    change(&a, &b);
    return 0;
}

void change(int *a, int *b) {
    int t = a;
    *a = *b;
    *b = *t;
}

I have a problem understanding how to save a copy of a and point to it from b later.

Answer 1

You do it like this:

int temp = *a; // remember actual value "a" points to
*a = *b; // copy value "b" points to onto value "a" points to (will overwrite that value, but we have a copy in "temp")
*b = temp; // now copy value "a" originally pointed to onto value "b" points to