Test your basic knowledge |

iOS 5 App Development 2

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. Instead of 'include' statements - in Objective-C we use _______ which does ________
A framework.
No - it gets the data from the controller.
Yes. The controller knows everything about the model.
Import / handle multiple inclusion.

2. How many superviews does a view have? How many subviews?
NSUserDefaults - which stores a property list.
One; zero to many
NSNumber. For example numberWithDouble: and doubleValue:
self.view

3. How to do enumeration with NSArray - NSDictionary - etc?

4. What does 'weak' mean?

5. The single-view template in Xcode does not...
No. It's fine.
Import / handle multiple inclusion.
Never!
create a model

6. What is static typing? Why is it good?

7. All classes should have a __________________ to be called by subclasses.
Cocoa Touch - Media - Core Services - Core OS
Designated initializer.
Wrap it in NSValue. And remember that NSValue immutable.
[[UIView alloc] initWithFrame]

8. What about controller talking to the model?
'Keep this in the heap until I don't point to anymore.' I won't point to it anymore if I set my pointer to nil - or if I am removed from the heap because no one points strongly to me.
[Class respondsToSelector:@selector(aMethod)]
Yes. The controller knows everything about the model.
Designated initializer.

9. Is NSArray mutable?
(1) We can validate (e.g. bounds-check) any sets done by a subclass. (2) We can lazily instantiate - so things only get created if and when they are needed.
id; an object pointer
No. Use NSMutableArray - which is a subclass of NSArray.
[Object isMemberOfClass:[Classname class]]

10. How to see all actions - outlets - incoming/outgoing segues on a view?
self = [super init] {if init is the designated initializer of the superclass}. If the superclass init routine fails - I will know to return nil from my init routine.
Points - to achieve device-independence
Yes. The controller knows everything about the model.
Right-click on view - or even a subview like a button.

11. What do I use for an unordered collection - e.g. test for membership? And is it mutable?

12. What is the makeup of a CGSize?
Getter and setter methods.
self = [super init] {if init is the designated initializer of the superclass}. If the superclass init routine fails - I will know to return nil from my init routine.
No...but it has 'a way' to notify the controller to come ask for fresh data.
Two floats - for width and height

13. List the iOS hierarchy from top to bottom.
1) Create a context 2) Create paths 3) Set colors - fonts - widths 4) Stroke or fill the above-created paths.
[Class respondsToSelector:@selector(aMethod)]
Two CGFloats for x and y
Cocoa Touch - Media - Core Services - Core OS

14. What do I use for a hash table/associative array? And is it mutable?

15. A _______ is how a view notifies the controller of something - for example - a button press.
UIWindow
addSubview; removeFromSubview
zero/nil
Action

16. Can the controller talking to the view?
One; zero to many
Yes. As much as it wants.
No. It's fine.
[[UIView alloc] initWithFrame]

17. Objects in an array: are the pointed to strongly or weakly?
Strongly.
At runtime.
(1) We can validate (e.g. bounds-check) any sets done by a subclass. (2) We can lazily instantiate - so things only get created if and when they are needed.
'Keep this in the heap until I don't point to anymore.' I won't point to it anymore if I set my pointer to nil - or if I am removed from the heap because no one points strongly to me.

18. Is it always bad to send messages to id?

19. What is the frame property of a UIView?

20. What is the base class for most objects in the iOS SDK?
constant NSString
Outlet; Action
MVC - for model-view-controller
NSObject

21. What is at the top of the view hierarchy?
self.view
At runtime.
UIWindow
Wrap it in NSValue. And remember that NSValue immutable.

22. ________ implements the getter and setter. But we can always__________
Call setNeedsDisplay:
zero/nil
NSObject
@synthesize; write our own getter and/or setter.

23. ______ is a pointer
@synthesize; write our own getter and/or setter.
Center of the frame - which is in the superview's coordinate system
self
addSubview; removeFromSubview

24. A _______ goes from the Controller to the View. A ________ goes from the view to the controller.
No. It's fine.
Lazy instantiation.
Center of the frame - which is in the superview's coordinate system
Outlet; Action

25. Where do I initialize properties?
The runtime system asks the object what its class is.
In the getter! This is called lazy instantiation.
A framework.
NSUserDefaults - which stores a property list.

26. How to tell whether an object implements a particular method? (A line of code)
On left side - is calling the setter - and on the right side - is calling the getter.
My rectangle in my superview's coordinate space
Import / handle multiple inclusion.
[Class respondsToSelector:@selector(aMethod)]

27. Talk about NSString
self
[Object isMemberOfClass:[Classname class]]
Can handle any language because it uses Unicode.
An outlet.

28. How to force a redraw of a custom area?
The document; possibly a database.
Designated initializer.
Call setNeedsDisplay:
NSLog; %@; %d and other formatters

29. When happens when you send a message to nil?
Import / handle multiple inclusion.
Sort of - in ways that it doesn't need to know much about the controller. For example: delegation.
Nothing happens - and nil is returned.
A rectangular area

30. In synthesize: @synthesize foo = _foo; The __foo_ is the ____________ or also known as the ___________________.

31. There is no difference between _____ and _______ at runtime.
Right-click on view - or even a subview like a button.
id; an object pointer
Lazy instantiation.
No...but it has 'a way' to notify the controller to come ask for fresh data.

32. What about public/private in Objective-C?

33. What is in the model?
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];
Outlet; Action
The document; possibly a database.
@synthesize; write our own getter and/or setter.

34. What does 'strong' mean?

35. Are local pointers to objects strong or weak? So what happens at the end of the routine?
option-click; option-double-click
NSSet; no - it's immutable
Strong. Object memory is freed at the end of the routine.
Import / handle multiple inclusion.

36. Instance methods start with a ______ and class methods start with a ______.
Points - to achieve device-independence
To zero; so pointers are nil.
Can handle any language because it uses Unicode.
Dash - Plus sign.

37. Calling a method on id works just fine because....?
[[UIView alloc] initWithFrame]
Strong. Object memory is freed at the end of the routine.
The runtime system asks the object what its class is.
option-click; option-double-click

38. What is the fundamental design pattern of iOS development?
Action
A collection of collections in graph form. Can include NSArray - NSDictionary - NSNumber - NSString - NSData - and NSData.
MVC - for model-view-controller
NO is zero; YES is anything else.

39. What is the bounds property of a UIView?
internal origin and size. Use this inside a view
Instance method; class method.
self
One; zero to many

40. Dot notation does what?
The runtime system asks the object what its class is.
Two floats - for width and height
Don't use id for a pointer. Use the actual type pointed to. It allows the compiler (but not the runtime!) to help find bugs.
On left side - is calling the setter - and on the right side - is calling the getter.

41. What is a reason to write our own setter?
Action
Introspection - with the class method 'class'
Argument validation.
To zero; so pointers are nil.

42. The view is...

43. How to create a UIView in code?
Never!
[[UIView alloc] initWithFrame]
A collection of collections in graph form. Can include NSArray - NSDictionary - NSNumber - NSString - NSData - and NSData.
self = [super init] {if init is the designated initializer of the superclass}. If the superclass init routine fails - I will know to return nil from my init routine.

44. The basic steps in custom drawing.
Other MVC trios.
Sort of - in ways that it doesn't need to know much about the controller. For example: delegation.
self
1) Create a context 2) Create paths 3) Set colors - fonts - widths 4) Stroke or fill the above-created paths.

45. How to access the controller's top view?
UIWindow
self.view
addSubview; removeFromSubview
If it's in the header file - it's public. To make some private variables - you can put a private interface section at the top of an implementation file.

46. What is an example of a reason to write a getter?
[[UIView alloc] initWithFrame]
Strong. Object memory is freed at the end of the routine.
Designated initializer.
Lazy instantiation.

47. How is ARC done?
The compiler adds code to count references.
Import / handle multiple inclusion.
the controller's minions. Gets things to the screen.
option-click; option-double-click

48. You can send a message to a...
Properties; instance variables
constant NSString
The document; possibly a database.
Wrap it in NSValue. And remember that NSValue immutable.

49. Use ______ to send debugging messages to the console. Use _____ for any object - which should return an string. Can also use ______.
Don't use id for a pointer. Use the actual type pointed to. It allows the compiler (but not the runtime!) to help find bugs.
NSSet; no - it's immutable
NSLog; %@; %d and other formatters
Cocoa Touch - Media - Core Services - Core OS

50. In the initializer methods of objects I create - add what line of code? Why?
The compiler adds code to count references.
NSNumber. For example numberWithDouble: and doubleValue:
self = [super init] {if init is the designated initializer of the superclass}. If the superclass init routine fails - I will know to return nil from my init routine.
NSSet; no - it's immutable