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 setters for outlets are called by _______ at this point ______________.
iOS; when the view is loaded.
self
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];
Never!

2. A property is just the combination of _______.
NSUserDefaults - which stores a property list.
1) Create a context 2) Create paths 3) Set colors - fonts - widths 4) Stroke or fill the above-created paths.
Action
Getter and setter methods.

3. Dot notation does what?
Other MVC trios.
On left side - is calling the setter - and on the right side - is calling the getter.
Immutable. But there are many methods that take an NSString and returned a modified one. This is fast and preferable to using NSMutableString.
The compiler adds code to count references.

4. How many superviews does a view have? How many subviews?
Override drawRect:
One; zero to many
Dash - Plus sign.
Class XX = [Object class]

5. What about controller talking to the model?
self.view
The compiler adds code to count references.
To zero; so pointers are nil.
Yes. The controller knows everything about the model.

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

7. Class methods are used for ___________ and the call starts with ____________.
Instance variable (ivar) or 'backing variable'
iOS; when the view is loaded.
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.

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

9. Where do I initialize properties?
[[UIView alloc] initWithFrame]
Interface; Implementation
In the getter! This is called lazy instantiation.
Other MVC trios.

10. What is at the top of the view hierarchy?
Points - to achieve device-independence
[[UIView alloc] initWithFrame]
Properties; instance variables
UIWindow

11. What is the fundamental design pattern of iOS development?
One; zero to many
MVC - for model-view-controller
The runtime system asks the object what its class is.
zero/nil

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

13. What is a property list?
A collection of collections in graph form. Can include NSArray - NSDictionary - NSNumber - NSString - NSData - and NSData.
NSNumber. For example numberWithDouble: and doubleValue:
UIWindow
NSData

14. What is used in lieu of pixels? And why?
At runtime.
Nothing happens - and nil is returned.
To zero; so pointers are nil.
Points - to achieve device-independence

15. How about the model talking to the controller?

16. Calling a method on id works just fine because....?
option-click; option-double-click
The runtime system asks the object what its class is.
No...but it has 'a way' to notify the controller to come ask for fresh data.
The document; possibly a database.

17. The view is...

18. What about the model and the view talking to one another?
The document; possibly a database.
Dash - Plus sign.
No. Use NSMutableArray - which is a subclass of NSArray.
Never!

19. When is it OK to call drawRect: directly?
Yes. As much as it wants.
No...but it has 'a way' to notify the controller to come ask for fresh data.
Never!
for...in; don't change things inside the loop.

20. ______ is a pointer to any object.
Argument validation.
[Class respondsToSelector:@selector(aMethod)]
id
[[UIView alloc] initWithFrame]

21. In the initializer methods of objects I create - add what line of code? Why?
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.
line up the colons!
In the getter! This is called lazy instantiation.
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];

22. How to tell whether an object implements a particular method? (A line of code)
[Class respondsToSelector:@selector(aMethod)]
Outlet; Action
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.
1) Create a context 2) Create paths 3) Set colors - fonts - widths 4) Stroke or fill the above-created paths.

23. What does 'strong' mean?

24. ________ is the .h file and __________ is the .m file.
Interface; Implementation
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.
The runtime system asks the object what its class is.
Nothing happens - and nil is returned.

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

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

27. What is an example of a reason to write a getter?
A framework.
for...in; don't change things inside the loop.
To zero; so pointers are nil.
Lazy instantiation.

28. What is the makeup of a CGSize?
Two floats - for width and height
[Object isMemberOfClass:[Classname class]]
Import / handle multiple inclusion.
Lazy instantiation.

29. What is the iOS term for a library?
@interface JGEmailLoginEmailViewController(){ NSMutableData _receivedData; }@property (weak -nonatomic) JGAppDelegate appDelegate;@property (weak - nonatomic) IBOutlet UITextField *txtfldEmailAddress;@end
iOS; when the view is loaded.
Never!
A framework.

30. What is the makeup of a CGPoint?
UIViewController.
Two CGFloats for x and y
[[UIView alloc] initWithFrame]
To zero; so pointers are nil.

31. The controller is always a subclass of...?
UIViewController.
Action
1) Create a context 2) Create paths 3) Set colors - fonts - widths 4) Stroke or fill the above-created paths.
MVC - for model-view-controller

32. 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.
Yes. The controller knows everything about the model.
for...in; don't change things inside the loop.
NSNumber. For example numberWithDouble: and doubleValue:

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

34. How to create a UIView in code?
To zero; so pointers are nil.
[[UIView alloc] initWithFrame]
Instance method; class method.
zero/nil

35. Instead of 'include' statements - in Objective-C we use _______ which does ________
iOS; when the view is loaded.
Import / handle multiple inclusion.
Outlet; Action
Sort of - in ways that it doesn't need to know much about the controller. For example: delegation.

36. There is no difference between _____ and _______ at runtime.
NSObject
[[UIView alloc] initWithFrame]
Wrap it in NSValue. And remember that NSValue immutable.
id; an object pointer

37. What if I want to put a scalar into an NSArray or NSSet?
Wrap it in NSValue. And remember that NSValue immutable.
@synthesize; write our own getter and/or setter.
In the getter! This is called lazy instantiation.
NSData

38. What does 'weak' mean?

39. In a nutshell: how to do custom drawing?
create a model
Instance variable (ivar) or 'backing variable'
No. Use NSMutableArray - which is a subclass of NSArray.
Override drawRect:

40. When happens when you send a message to nil?
Properties; instance variables
Controls how the model is presented onscreen.
[Object isMemberOfClass:[Classname class]]
Nothing happens - and nil is returned.

41. What is the frame property of a UIView?

42. Some controllers have ____________ as their views.
The runtime system asks the object what its class is.
NSSet; no - it's immutable
Outlet; Action
Other MVC trios.

43. How to add subviews in code? How to remove them?
One; zero to many
addSubview; removeFromSubview
Yes. As much as it wants.
(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.

44. Talk about NSString
Import / handle multiple inclusion.
Can handle any language because it uses Unicode.
addSubview; removeFromSubview
The runtime system asks the object what its class is.

45. Remember that it's cool to...
Getter and setter methods.
line up the colons!
NSDictionary; no - it's immutable.
Instance variable (ivar) or 'backing variable'

46. How to tell if an object is of a particular class? (Write a line of code)
id
[Object isMemberOfClass:[Classname class]]
Instance method; class method.
Properties; instance variables

47. What is the makeup of a CGRect?
Immutable. But there are many methods that take an NSString and returned a modified one. This is fast and preferable to using NSMutableString.
A CGPoint and and a CGSize
create a model
[Class respondsToSelector:@selector(aMethod)]

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

49. What do I use for a bag of bits?
Never!
Properties; instance variables
Action
NSData

50. 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];
Sort of - in ways that it doesn't need to know much about the controller. For example: delegation.
Interface; Implementation
No...but it has 'a way' to notify the controller to come ask for fresh data.