Building and Running Your Application

It's really a blast to see what you get when you build and run a project that you created - even if all you did was choose a template from the Project window. Building and running a project is relatively simple:

1. If it isn't already chosen, choose Simulator - 4.2 | Debug from the Overview drop-down menu in the top-left corner of the Project window to set the active SDK and Active Build Configuration.
   This combination (Simulator - 4.2 | Debug) may be chosen already. Here's what that means:
   • When you download an SDK, you may actually download multiple SDKs - a Simulator SDK and a device SDK for each of the current iOS releases.
   • The one to use for iPad development is the iPad Simulator 4.2 SDK for iOS 4.2. Later, you can switch to the actual device SDK and download your app to a real-world iPad. But before you do that, there's just one catch.
   • You have to be in the iOS Developer Program to run your app on a device, even on your very own iPad.
   A build configuration tells Xcode the purpose of the built product. You can choose between Debug, which has features to help with debugging (there's a no-brainer for you); and Release, which results in smaller and faster binaries. You use Debug most of the time as you develop an app - so go with Debug for now. (Choose Simulator - 4.2 | Debug from the Overview drop-down menu.)
2. Choose Build → Build and Run from the main menu to build and run the application.
   Click the Build and Run button in the Project Window toolbar. The status bar in the Project window tells you all about build progress, build errors such as compiler errors, or warnings - and (oh, yeah) whether the build was successful.
   You can also display the Build Results window by clicking the Succeeded message in the Status bar.

After it's launched in the Simulator. You should see the gray status bar and a white window, and the simulated Home button on the bottom to quit your app, but that's it. You can also choose actions in the Hardware menu.