I went through an apple cocoa tutorial and found it quick and easy to create a user interface (to be honest didnt get the code that much, as all I know is C++ and just started OOP) and I was wondering can you do the same using xcode for a C++ app.
Yes, you need to use Carbon if you want to program in C++, and I don't think you can use interface builder with Carbon.
However, Objective C is very easy to learn if you already know C++. It'll take you less than an hour to grasp the basics and become productive. And if you work with it for a week you'll be comfortable with the syntax and have most of the mechanisms and design patterns under control.
If you don't want to limit yourself to Mac apps (yes, I know, I know, but there are other systems out there, really... ), then you could check out Qt from Trolltech, a cross-platform framework for making GUIs for C++ developers...
I think you can use Interface Builder with Carbon but I could be wrong. Cocoa and Carbon can achieve the same results but it's generally thought that it's easier for a single developer/small team to do it in Cocoa. Apple are throwing a lot of technology and development at Cocoa whereas Carbon seems to be static at the moment.
Yes, I'm pretty sure you can use Carbon with IB. And there's also some unholy beast called Objective-C++, which Xcode/gcc supports, so that might help you. But that said, it's still generally best to stick with Objective-C/C/Cocoa for new, native Mac apps.
I'm sorry. You can use Interface Builder with Carbon. I have only used it with Cocoa and assumed, since all the UI-controls in the palette were called NSSomething and only had documentation for Objective C and Java, that it was Objective C and Java only.
I tried creating a Carbon project and it does use Interface Builder, and the UI-control palette is now replaced with different controls.