The Target in Xcode

A target is a collection of parts along with rules and settings for how to build a product from them. Whenever you build, what you’re really building is a target.

Select the Empty Window project at the top of the Project navigator, and you’ll see two things on the left side of the editor: the project itself, and a list of your targets. (This list can appear either as a column on the left side of the editor, as in Figure 6-8, or as a pop- up menu at the top left of the editor if that column is collapsed to save space.) Our Empty Window project comes with two targets: the app target, called Empty Window (just like the project itself), and the tests target, called Empty WindowTests. 

Under certain cir‐ cumstances, you might add further targets to a project. For example, you might want to write an app that can be built as an iPhone app or as an iPad app — two different apps that share a lot of the same code. So you might want one project that builds both apps through separate targets.

If you select the project in the left column or pop-up menu of the editor, you edit the project. If you select a target in the left column or pop-up menu of the editor, you edit the target. I’ll use those expressions a lot in later instructions.

Let’s concentrate on the app target, Empty Window. This is the target that you use to build and run your app. Its settings are the settings that tell Xcode how your app is to be built; its product is the app itself. (The tests target, Empty WindowTests, creates a special executable whose purpose is to test your app’s code.