Passing Pointers to a Function

ByWalter Wimberly

We’ve seen the benefits of passing variables by reference to a function. It allows you to change their value inside the function. Well, when we pass by reference, this is essentially using pointers – you just didn’t realize it.

Therefore you can have instances like:

void swap(int* x, int* y)
{
  int* temp = x;
  x = y;
  y = temp;
}

int main()
{
    int x = 5;
    int y = 10;

    cout << x << endl;
    cout << y << endl;
    swap(x, y);
    cout << x << endl;
    cout << y << endl;

    return 0;
}

Alternatively I can write it with passing the memory address and references.

void swap(int* x, int* y)
{
  int temp = *x;
  *x = *y;
  *y = temp;
}

int main()
{
    int x = 5;
    int y = 10;

    cout << x << endl;
    cout << y << endl;
    swap(&x, &y);
    cout << x << endl;
    cout << y << endl;

    return 0;
}

Passing Pointers to a Function was originally found on Access 2 Learn

Assistant Professor

Walter Wimberly is an Assistant Professor at a regional college in Tennessee, teaching Computer Science in the Software Engineering track. He works as a student advisor, oversees curriculum changes, develops new courses, and manages the advisory panel.
Walter taught full time for about 7 years, before going back into “industry” as a full stack Software Developer for a dozen years. There he focused on web based projects coding in JavaScript/jQuery and utilizing the Bootstrap CSS Framework on the front-end, and coding in PHP, ASP/ASP.Net, SQL on the back-end.

Since he loves teaching, he taught as an adjunct web and digital media classes for eight (8) years, while working in industry, and has since returned to teaching full time.

He has been married for over 25 years, and is father to several special needs boys. As such, he is working on some projects to help others who have special needs to be self-sufficient, and support the care givers of those with special needs. Check out his Autism blog for more info.

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