Installing Xcode and Compiling Objective-C on Mac OS X
In later chapters we will look at how to install and use Objective-C on Windows and Linux systems for those that do not have access to Mac OS X. If you are planning to develop iPhone applications (or Mac OS X applications for that matter), however, you are going to need to use an Intel based Mac OS X system at some point in the future.
Perhaps the biggest advantage of using Mac OS X as your Objective-C learning platform (aside from the ability to develop iPhone and Mac OS X applications) is the fact that you get to use Apple's Xcode development tool. Xcode is a powerful and easy to use development environment that is available free of charge to anyone fortunate enough to own an Apple computer running Mac OS X.
In this chapter we will cover the steps involved in installing Xcode and writing and compiling a simple Objective-C program in this environment. For those readers that prefer to do their coding and compiling in at the command prompt we will then cover use of Objective-C in a terminal window.
Installing Xcode on Mac OS X
Xcode may or may not be pre-installed on your Mac OS X system. To find out if you already have it, open the Finder and look for it in the Developer subfolder of the Applications folder. If the Developer folder does not exist, or does not contain Xcode then you will need to install it.
The best way to obtain Xcode is to download it from the Apple web site. it can also be installed from the Developer Tools installation disk if you happen to have one, but most Mac systems do not ship with this. The URL to download Xcode is http://developer.apple.com/technology/xcode.html. there are two forms of Xcode, one for developing iPhone applications and the other for developing Mac OS X applications. in order to download Xcode, you will need either a Registered iPhone Developer account (in the case of the iphone Xcode) or an ADC membership (in the case of the MAC OS X Xcode). Fortunately, both of these memberships are free and can be activated using your existing Apple account (for example the one you use to buy music on iTunes).
Once you have registered, you will gain access to the Apple Developer Connection web site where download links are provided for Xcode on a variety of Mac OS X versions.
The download will take a number of hours to complete depending on the speed of your internet connection and take the form of a disk image (.dmg) file.
