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. Is NSString mutable or not?
Immutable. But there are many methods that take an NSString and returned a modified one. This is fast and preferable to using NSMutableString.
self.view
Two floats - for width and height
NSData

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

3. Can the controller talking to the view?
Yes. As much as it wants.
A collection of collections in graph form. Can include NSArray - NSDictionary - NSNumber - NSString - NSData - and NSData.
One; zero to many
id

4. What is used in lieu of pixels? And why?
Points - to achieve device-independence
Lazy instantiation.
Other MVC trios.
My rectangle in my superview's coordinate space

5. What is the bounds property of a UIView?
Two floats - for width and height
the controller's minions. Gets things to the screen.
internal origin and size. Use this inside a view
[Object isKindOfClass:[Classname class]]

6. What do I use for a bag of bits?
id
Points - to achieve device-independence
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.

7. You can send a message to a...
To zero; so pointers are nil.
constant NSString
[Object isKindOfClass:[Classname class]]
id

8. How to force a redraw of a custom area?
Call setNeedsDisplay:
@synthesize; write our own getter and/or setter.
No. Use NSMutableArray - which is a subclass of NSArray.
internal origin and size. Use this inside a view

9. Where do I initialize properties?
Introspection - with the class method 'class'
A framework.
A CGPoint and and a CGSize
In the getter! This is called lazy instantiation.

10. How is ARC done?
The compiler adds code to count references.
Right-click on view - or even a subview like a button.
Action
NSObject

11. How many superviews does a view have? How many subviews?
Lazy instantiation.
NSNumber. For example numberWithDouble: and doubleValue:
Two CGFloats for x and y
One; zero to many

12. Show a private interface section.
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.
Strongly.
@interface JGEmailLoginEmailViewController(){ NSMutableData _receivedData; }@property (weak -nonatomic) JGAppDelegate appDelegate;@property (weak - nonatomic) IBOutlet UITextField *txtfldEmailAddress;@end
id; an object pointer

13. How about the model talking to the controller?

14. A _______ goes from the Controller to the View. A ________ goes from the view to the controller.
Controls how the model is presented onscreen.
NSDictionary; no - it's immutable.
The runtime system asks the object what its class is.
Outlet; Action

15. What to do in Xcode for short documentation? For full documentation?
Outlet; Action
option-click; option-double-click
NSDictionary; no - it's immutable.
Interface; Implementation

16. When happens when you send a message to nil?
Nothing happens - and nil is returned.
@synthesize; write our own getter and/or setter.
Strong. Object memory is freed at the end of the routine.
NSLog; %@; %d and other formatters

17. ________ implements the getter and setter. But we can always__________
the controller's minions. Gets things to the screen.
Instance variable (ivar) or 'backing variable'
@synthesize; write our own getter and/or setter.
NSDictionary; no - it's immutable.

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

19. If I need to convert a number to an object - use __________
Wrap it in NSValue. And remember that NSValue immutable.
[Object isKindOfClass:[Classname class]]
NSNumber. For example numberWithDouble: and doubleValue:
self.view

20. The view is...

21. How can I save user information between launches of my app?
addSubview; removeFromSubview
NSUserDefaults - which stores a property list.
Cocoa Touch - Media - Core Services - Core OS
NSObject

22. What if I want to put a scalar into an NSArray or NSSet?
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.
create a model
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.

23. What does the controller do?
@interface JGEmailLoginEmailViewController(){ NSMutableData _receivedData; }@property (weak -nonatomic) JGAppDelegate appDelegate;@property (weak - nonatomic) IBOutlet UITextField *txtfldEmailAddress;@end
Designated initializer.
Controls how the model is presented onscreen.
Creating objects - or finding information relative to the class. The name of the class is the first thing in the square brackets.

24. What is the frame property of a UIView?

25. What is a reason to write our own setter?
NSArray; no - it's immutable.
id; an object pointer
Argument validation.
Never!

26. Talk about BOOL variables.
NO is zero; YES is anything else.
Strongly.
Introspection - with the class method 'class'
Dash - Plus sign.

27. What about the view talking to the controller?

28. What does 'weak' mean?

29. What is the center property of a UIView?

30. What does a view (UIView) represent?
id; an object pointer
A rectangular area
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.
Creating objects - or finding information relative to the class. The name of the class is the first thing in the square brackets.

31. How can I find out the class of any object? Give a line of code.
Designated initializer.
Wrap it in NSValue. And remember that NSValue immutable.
Instance method; class method.
Class XX = [Object class]

32. All classes should have a __________________ to be called by subclasses.
[Object isKindOfClass:[Classname class]]
Designated initializer.
NSNumber. For example numberWithDouble: and doubleValue:
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];

33. What is the base class for most objects in the iOS SDK?
Call setNeedsDisplay:
MVC - for model-view-controller
NSObject
No...but it has 'a way' to notify the controller to come ask for fresh data.

34. How to create a UIView in code?
No. Use NSMutableArray - which is a subclass of NSArray.
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.
[[UIView alloc] initWithFrame]
NSArray; no - it's immutable.

35. Remember that it's cool to...
line up the colons!
NSDictionary; no - it's immutable.
the controller's minions. Gets things to the screen.
Action

36. How to tell if an object is of a particular class? (Write a line of code)
addSubview; removeFromSubview
Instance variable (ivar) or 'backing variable'
[Object isMemberOfClass:[Classname class]]
Action

37. Objects in an array: are the pointed to strongly or weakly?
An outlet.
constant NSString
line up the colons!
Strongly.

38. What is the name of a property in the controller that it uses to talk to views?
No. Use NSMutableArray - which is a subclass of NSArray.
Instance variable (ivar) or 'backing variable'
iOS; when the view is loaded.
An outlet.

39. How to tell whether an object implements a particular method? (A line of code)
[Class respondsToSelector:@selector(aMethod)]
Strong. Object memory is freed at the end of the routine.
Cocoa Touch - Media - Core Services - Core OS
NO is zero; YES is anything else.

40. Instance methods start with a ______ and class methods start with a ______.
1) Create a context 2) Create paths 3) Set colors - fonts - widths 4) Stroke or fill the above-created paths.
Dash - Plus sign.
An outlet.
In the getter! This is called lazy instantiation.

41. What is a property list?
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.
Sort of - in ways that it doesn't need to know much about the controller. For example: delegation.
UIViewController.
A collection of collections in graph form. Can include NSArray - NSDictionary - NSNumber - NSString - NSData - and NSData.

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

43. What is the makeup of a CGRect?
NO is zero; YES is anything else.
No...but it has 'a way' to notify the controller to come ask for fresh data.
The document; possibly a database.
A CGPoint and and a CGSize

44. The controller is always a subclass of...?
UIViewController.
To zero; so pointers are nil.
@interface JGEmailLoginEmailViewController(){ NSMutableData _receivedData; }@property (weak -nonatomic) JGAppDelegate appDelegate;@property (weak - nonatomic) IBOutlet UITextField *txtfldEmailAddress;@end
An outlet.

45. All properties are initialized to _____
Interface; Implementation
Center of the frame - which is in the superview's coordinate system
The compiler adds code to count references.
zero/nil

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

47. Does a view 'own' the data it displays?
NSDictionary; no - it's immutable.
No - it gets the data from the controller.
Lazy instantiation.
UIViewController.

48. When is it OK to call drawRect: directly?
zero/nil
Interface; Implementation
id
Never!

49. Dot notation does what?
On left side - is calling the setter - and on the right side - is calling the getter.
Center of the frame - which is in the superview's coordinate system
Right-click on view - or even a subview like a button.
Sort of - in ways that it doesn't need to know much about the controller. For example: delegation.

50. 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.
NSSet; no - it's immutable
A framework.
NSLog; %@; %d and other formatters