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. How is ARC done?
Sort of - in ways that it doesn't need to know much about the controller. For example: delegation.
Action
[Class respondsToSelector:@selector(aMethod)]
The compiler adds code to count references.

2. What do I use for an ordered collection of objects? And is it mutable?

3. If a method starts with a dash - it's a ___________. If it starts with a plus sign - it's a ______________.
A collection of collections in graph form. Can include NSArray - NSDictionary - NSNumber - NSString - NSData - and NSData.
Can handle any language because it uses Unicode.
Instance method; class method.
Strong. Object memory is freed at the end of the routine.

4. How can I find out the class of any object? Give a line of code.
'Keep this in the heap as long as someone else points to it strongly. If it gets thrown out of the heap - set my pointer to it to nil.'
No. It's fine.
Class XX = [Object class]
NO is zero; YES is anything else.

5. What is the makeup of a CGSize?
Two floats - for width and height
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];
UIWindow
No...but it has 'a way' to notify the controller to come ask for fresh data.

6. What is the bounds property of a UIView?
option-click; option-double-click
create a model
internal origin and size. Use this inside a view
The document; possibly a database.

7. A _______ goes from the Controller to the View. A ________ goes from the view to the controller.
Yes. As much as it wants.
Outlet; Action
Argument validation.
NSArray; no - it's immutable.

8. What does the controller do?
Controls how the model is presented onscreen.
Cocoa Touch - Media - Core Services - Core OS
NSUserDefaults - which stores a property list.
My rectangle in my superview's coordinate space

9. The basic steps in custom drawing.
1) Create a context 2) Create paths 3) Set colors - fonts - widths 4) Stroke or fill the above-created paths.
Argument validation.
Immutable. But there are many methods that take an NSString and returned a modified one. This is fast and preferable to using NSMutableString.
Never!

10. The controller is always a subclass of...?
Interface; Implementation
Can handle any language because it uses Unicode.
Outlet; Action
UIViewController.

11. The setters for outlets are called by _______ at this point ______________.
Other MVC trios.
Designated initializer.
UIViewController.
iOS; when the view is loaded.

12. What is in the model?
UIViewController.
@interface JGEmailLoginEmailViewController(){ NSMutableData _receivedData; }@property (weak -nonatomic) JGAppDelegate appDelegate;@property (weak - nonatomic) IBOutlet UITextField *txtfldEmailAddress;@end
The document; possibly a database.
Two CGFloats for x and y

13. ________ is the .h file and __________ is the .m file.
Interface; Implementation
Never!
The document; possibly a database.
NSArray; no - it's immutable.

14. How about the model talking to the controller?

15. Is NSArray mutable?
NSUserDefaults - which stores a property list.
No. Use NSMutableArray - which is a subclass of NSArray.
create a model
Properties; instance variables

16. List the iOS hierarchy from top to bottom.
NSData
Cocoa Touch - Media - Core Services - Core OS
create a model
addSubview; removeFromSubview

17. What if I want to put a scalar into an NSArray or NSSet?
An outlet.
Wrap it in NSValue. And remember that NSValue immutable.
NSNumber. For example numberWithDouble: and doubleValue:
Never!

18. Why are properties good?
the controller's minions. Gets things to the screen.
Interface; Implementation
iOS; when the view is loaded.
(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.

19. What is a property list?
Nothing happens - and nil is returned.
No - it gets the data from the controller.
A collection of collections in graph form. Can include NSArray - NSDictionary - NSNumber - NSString - NSData - and NSData.
addSubview; removeFromSubview

20. The decision on what method to call is made when?
Dash - Plus sign.
Wrap it in NSValue. And remember that NSValue immutable.
At runtime.
MVC - for model-view-controller

21. Dot notation does what?
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];
[Object isMemberOfClass:[Classname class]]
Outlet; Action
On left side - is calling the setter - and on the right side - is calling the getter.

22. Calling a method on id works just fine because....?
Instance method; class method.
(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.
The runtime system asks the object what its class is.
zero/nil

23. What about controller talking to the model?
id
Yes. The controller knows everything about the model.
constant NSString
internal origin and size. Use this inside a view

24. How can I save user information between launches of my app?
Immutable. But there are many methods that take an NSString and returned a modified one. This is fast and preferable to using NSMutableString.
for...in; don't change things inside the loop.
Instance variable (ivar) or 'backing variable'
NSUserDefaults - which stores a property list.

25. What does a view (UIView) represent?
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.
Creating objects - or finding information relative to the class. The name of the class is the first thing in the square brackets.
An outlet.
A rectangular area

26. In a nutshell: how to do custom drawing?
[Object isKindOfClass:[Classname class]]
Cocoa Touch - Media - Core Services - Core OS
Override drawRect:
Sort of - in ways that it doesn't need to know much about the controller. For example: delegation.

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

28. What is a reason to write our own setter?
Argument validation.
Yes. As much as it wants.
UIWindow
Two CGFloats for x and y

29. The view is...

30. What is the base class for most objects in the iOS SDK?
UIViewController.
option-click; option-double-click
NSObject
[Object isMemberOfClass:[Classname class]]

31. There is no difference between _____ and _______ at runtime.
[Object isMemberOfClass:[Classname class]]
NO is zero; YES is anything else.
[[UIView alloc] initWithFrame]
id; an object pointer

32. Instead of 'include' statements - in Objective-C we use _______ which does ________
A framework.
Import / handle multiple inclusion.
Never!
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.

33. What is the makeup of a CGRect?
A CGPoint and and a CGSize
zero/nil
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];
One; zero to many

34. Remember that it's cool to...
Never!
Override drawRect:
Right-click on view - or even a subview like a button.
line up the colons!

35. Does a view 'own' the data it displays?
Designated initializer.
Instance variable (ivar) or 'backing variable'
No - it gets the data from the controller.
for...in; don't change things inside the loop.

36. Class methods are used for ___________ and the call starts with ____________.
(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.
line up the colons!
Creating objects - or finding information relative to the class. The name of the class is the first thing in the square brackets.
addSubview; removeFromSubview

37. What to do in Xcode for short documentation? For full documentation?
option-click; option-double-click
addSubview; removeFromSubview
No. It's fine.
Interface; Implementation

38. A _______ is how a view notifies the controller of something - for example - a button press.
Override drawRect:
[[UIView alloc] initWithFrame]
Action
Immutable. But there are many methods that take an NSString and returned a modified one. This is fast and preferable to using NSMutableString.

39. How to instantiate an object?
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];
addSubview; removeFromSubview
Nothing happens - and nil is returned.
Yes. The controller knows everything about the model.

40. How many superviews does a view have? How many subviews?
id
One; zero to many
Argument validation.
[Class respondsToSelector:@selector(aMethod)]

41. Can the controller talking to the view?
'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.
Yes. As much as it wants.
constant NSString
A framework.

42. How to tell if an object is of a particular class? (Write a line of code)
A rectangular area
option-click; option-double-click
Yes. The controller knows everything about the model.
[Object isMemberOfClass:[Classname class]]

43. ________ implements the getter and setter. But we can always__________
@synthesize; write our own getter and/or setter.
@interface JGEmailLoginEmailViewController(){ NSMutableData _receivedData; }@property (weak -nonatomic) JGAppDelegate appDelegate;@property (weak - nonatomic) IBOutlet UITextField *txtfldEmailAddress;@end
NSDictionary; no - it's immutable.
UIViewController.

44. How to add subviews in code? How to remove them?
addSubview; removeFromSubview
id; an object pointer
The document; possibly a database.
option-click; option-double-click

45. What do I use for a bag of bits?
Strongly.
NSData
(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.
No. It's fine.

46. A property is just the combination of _______.
Getter and setter methods.
NSDictionary; no - it's immutable.
self.view
[Class respondsToSelector:@selector(aMethod)]

47. What is the iOS term for a library?
A rectangular area
UIWindow
@interface JGEmailLoginEmailViewController(){ NSMutableData _receivedData; }@property (weak -nonatomic) JGAppDelegate appDelegate;@property (weak - nonatomic) IBOutlet UITextField *txtfldEmailAddress;@end
A framework.

48. What is the frame property of a UIView?

49. What is an example of a reason to write a getter?
Call setNeedsDisplay:
NSDictionary; no - it's immutable.
self.view
Lazy instantiation.

50. What is at the top of the view hierarchy?
NSLog; %@; %d and other formatters
[Object isMemberOfClass:[Classname class]]
UIWindow
NSNumber. For example numberWithDouble: and doubleValue: