Maybe it's a stupid question, but anyways: How can I change 127.0.0.1 (localhost) to a domain name (www.example.com) for users to access worldwide? Is that possible? If it matters - I'm using XAMPP v1.8.3 Thank you.
To connect to your computer someone needs your IP. So first you must have a static IP (contact your internet provider for this) or at least use a service like this.
A domain name is a whole different process. As soon as you have your static IP try to experiment with a free domain service like this one here.
You should find instructions on the second site.
And one friendly advice: Please try to form your questions better. Do a little research by yourself and then ask a specific question IF you don't find the answer yourself. The question you asked is too general. Its like asking "Hey, how can I build a house?".
The answer you require on questions like that cannot be formed in a single forum response.
Best Regards.