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. The controller is always a subclass of...?
UIViewController.
One; zero to many
Interface; Implementation
id; an object pointer

2. Is NSArray mutable?
One; zero to many
No. Use NSMutableArray - which is a subclass of NSArray.
Yes. The controller knows everything about the model.
create a model

3. How about the model talking to the controller?

4. Where do I initialize properties?
In the getter! This is called lazy instantiation.
create a model
[Object isKindOfClass:[Classname class]]
zero/nil

5. All classes should have a __________________ to be called by subclasses.
Interface; Implementation
option-click; option-double-click
Designated initializer.
constant NSString

6. ______ is a pointer to any object.
A CGPoint and and a CGSize
The runtime system asks the object what its class is.
Lazy instantiation.
id

7. How to force a redraw of a custom area?
Call setNeedsDisplay:
Instance variable (ivar) or 'backing variable'
NSLog; %@; %d and other formatters
Can handle any language because it uses Unicode.

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

9. What does the controller do?
Introspection - with the class method 'class'
Cocoa Touch - Media - Core Services - Core OS
[Object isMemberOfClass:[Classname class]]
Controls how the model is presented onscreen.

10. How to tell if an object is of a particular class? (Write a line of code)
[Object isMemberOfClass:[Classname class]]
Right-click on view - or even a subview like a button.
The document; possibly a database.
NSArray; no - it's immutable.

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

12. What about the view talking to the controller?

13. Remember that it's cool to...
@interface JGEmailLoginEmailViewController(){ NSMutableData _receivedData; }@property (weak -nonatomic) JGAppDelegate appDelegate;@property (weak - nonatomic) IBOutlet UITextField *txtfldEmailAddress;@end
line up the colons!
the controller's minions. Gets things to the screen.
Argument validation.

14. What is at the top of the view hierarchy?
Points - to achieve device-independence
NSUserDefaults - which stores a property list.
In the getter! This is called lazy instantiation.
UIWindow

15. What is in the model?
The document; possibly a database.
An outlet.
Instance variable (ivar) or 'backing variable'
At runtime.

16. Instance methods start with a ______ and class methods start with a ______.
the controller's minions. Gets things to the screen.
At runtime.
NSArray; no - it's immutable.
Dash - Plus sign.

17. How to create a UIView in code?
[[UIView alloc] initWithFrame]
My rectangle in my superview's coordinate space
Wrap it in NSValue. And remember that NSValue immutable.
[Object isMemberOfClass:[Classname class]]

18. Some controllers have ____________ as their views.
1) Create a context 2) Create paths 3) Set colors - fonts - widths 4) Stroke or fill the above-created paths.
Yes. As much as it wants.
Other MVC trios.
Controls how the model is presented onscreen.

19. The basic steps in custom drawing.
UIWindow
The document; possibly a database.
(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.
1) Create a context 2) Create paths 3) Set colors - fonts - widths 4) Stroke or fill the above-created paths.

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

21. Why are properties good?
(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.
self.view
Cocoa Touch - Media - Core Services - Core OS
Yes. The controller knows everything about the model.

22. Calling a method on id works just fine because....?
iOS; when the view is loaded.
The runtime system asks the object what its class is.
NSUserDefaults - which stores a property list.
Outlet; Action

23. What about the model and the view talking to one another?
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.
Two CGFloats for x and y
self.view

24. How to tell whether an object implements a particular method? (A line of code)
Other MVC trios.
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.
[Class respondsToSelector:@selector(aMethod)]
Nothing happens - and nil is returned.

25. What does 'strong' mean?

26. Is NSString mutable or not?
Import / handle multiple inclusion.
Immutable. But there are many methods that take an NSString and returned a modified one. This is fast and preferable to using NSMutableString.
Designated initializer.
Sort of - in ways that it doesn't need to know much about the controller. For example: delegation.

27. How to tell whether an object is of a class or class that inherits from that class? (Write a line of code)
NSObject
[Object isKindOfClass:[Classname class]]
for...in; don't change things inside the loop.
A rectangular area

28. What is the word for checking/verifying the type of an object?

29. ________ implements the getter and setter. But we can always__________
To zero; so pointers are nil.
NSNumber. For example numberWithDouble: and doubleValue:
@synthesize; write our own getter and/or setter.
Other MVC trios.

30. Talk about BOOL variables.
Strongly.
No...but it has 'a way' to notify the controller to come ask for fresh data.
A CGPoint and and a CGSize
NO is zero; YES is anything else.

31. What is an example of a reason to write a getter?
NSData
Lazy instantiation.
Yes. As much as it wants.
The document; possibly a database.

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

33. How to see all actions - outlets - incoming/outgoing segues on a view?
Right-click on view - or even a subview like a button.
Yes. As much as it wants.
At runtime.
One; zero to many

34. All properties are initialized to _____
@interface JGEmailLoginEmailViewController(){ NSMutableData _receivedData; }@property (weak -nonatomic) JGAppDelegate appDelegate;@property (weak - nonatomic) IBOutlet UITextField *txtfldEmailAddress;@end
No...but it has 'a way' to notify the controller to come ask for fresh data.
zero/nil
Sort of - in ways that it doesn't need to know much about the controller. For example: delegation.

35. There is no difference between _____ and _______ at runtime.
To zero; so pointers are nil.
Controls how the model is presented onscreen.
id
id; an object pointer

36. What is used in lieu of pixels? And why?
An outlet.
Points - to achieve device-independence
No - it gets the data from the controller.
Right-click on view - or even a subview like a button.

37. How many superviews does a view have? How many subviews?
One; zero to many
In the getter! This is called lazy instantiation.
Introspection - with the class method 'class'
UIViewController.

38. How are local variables initialized in iOS 5?
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.
To zero; so pointers are nil.
Properties; instance variables
[Object isKindOfClass:[Classname class]]

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

40. How is ARC done?
line up the colons!
Two CGFloats for x and y
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];
The compiler adds code to count references.

41. What is the makeup of a CGRect?
Outlet; Action
A CGPoint and and a CGSize
addSubview; removeFromSubview
Action

42. Classes cannot have _________ or ___________.
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.
Wrap it in NSValue. And remember that NSValue immutable.
Properties; instance variables
Points - to achieve device-independence

43. Class methods are used for ___________ and the call starts with ____________.
Two floats - for width and height
One; zero to many
Creating objects - or finding information relative to the class. The name of the class is the first thing in the square brackets.
NSData

44. ______ is a pointer
Can handle any language because it uses Unicode.
self
[[UIView alloc] initWithFrame]
No. It's fine.

45. Use ______ to send debugging messages to the console. Use _____ for any object - which should return an string. Can also use ______.
Properties; instance variables
Interface; Implementation
NSLog; %@; %d and other formatters
On left side - is calling the setter - and on the right side - is calling the getter.

46. Instead of 'include' statements - in Objective-C we use _______ which does ________
the controller's minions. Gets things to the screen.
NSData
UIViewController.
Import / handle multiple inclusion.

47. What is the makeup of a CGPoint?
Two CGFloats for x and y
One; zero to many
line up the colons!
Never!

48. How to access the controller's top view?
NO is zero; YES is anything else.
Two floats - for width and height
self.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.

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

50. Are local pointers to objects strong or weak? So what happens at the end of the routine?
Getter and setter methods.
Creating objects - or finding information relative to the class. The name of the class is the first thing in the square brackets.
@synthesize; write our own getter and/or setter.
Strong. Object memory is freed at the end of the routine.