Objective-C Fundamentals

Hooking up the user interface
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Figure 1.7 Dragging and dropping new controls onto the view. Notice the snap lines, which help ensure your user
interface conforms to the iOS Human Interface Guidelines (HIG).
1.4.2 Connecting controls to source code
The user interface you just created meets these requirements, but the code can’t
determine which button should indicate that the user calls heads or tails (even if the
text on the buttons makes it inherently obvious to a human). Instead, you must explicitly
establish these connections. Xcode allows you to do so graphically.
Hold down the Control key and drag the button labeled Heads toward the icon
representing the CoinTossViewController instance (File’s Owner) located on the left
edge of the editor. As you drag, a blue line should appear between the two elements.
When you let go of the mouse, a pop-up menu appears that allows you to select
which message should be sent to the CoinTossViewController object whenever the