Quick Look Data Types
The Xcode debugger includes the variables Quick Look feature, a way to view the current state of object variables in your app by displaying their contents graphically in a pop-up display, either by clicking the Quick Look button in the debugger variables view or by pressing the Space bar with a variable selected.
Not all operating system object types can present quick looks, but many can. The following table lists common object types provided by the operating system that support Quick Look:
Attributed string class
You can always try the Quick Look feature if the object type isn’t in this list. If Quick Look isn’t available for the object type you’ve selected, Xcode shows the default Quick Look display for that object.
You can extend Quick Look for use with custom object types by adding a rendering method to the object class. See Quick Look for Custom Types in the Xcode Debuggerto learn how to implement Quick Look in your custom object classes.