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

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2. Calling a method on id works just fine because....?
UIWindow
[Class respondsToSelector:@selector(aMethod)]
The runtime system asks the object what its class is.
id; an object pointer


3. If I need to convert a number to an object - use __________
NSNumber. For example numberWithDouble: and doubleValue:
self
NSArray; no - it's immutable.
Two CGFloats for x and y


4. What do I use for a bag of bits?
NSData
Strong. Object memory is freed at the end of the routine.
for...in; don't change things inside the loop.
Right-click on view - or even a subview like a button.


5. You can send a message to a...
Two CGFloats for x and y
for...in; don't change things inside the loop.
UIViewController.
constant NSString


6. What about controller talking to the model?
@synthesize; write our own getter and/or setter.
Call setNeedsDisplay:
Yes. The controller knows everything about the model.
On left side - is calling the setter - and on the right side - is calling the getter.


7. ________ is the .h file and __________ is the .m file.
Interface; Implementation
Cocoa Touch - Media - Core Services - Core OS
[Class respondsToSelector:@selector(aMethod)]
Points - to achieve device-independence


8. In the initializer methods of objects I create - add what line of code? Why?
Two floats - for width and height
At runtime.
UIWindow
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.


9. How can I find out the class of any object? Give a line of code.
NSDictionary; no - it's immutable.
UIViewController.
Class XX = [Object class]
MVC - for model-view-controller


10. Instance methods start with a ______ and class methods start with a ______.
Dash - Plus sign.
id; an object pointer
Wrap it in NSValue. And remember that NSValue immutable.
'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.


11. What is the iOS term for a library?
A framework.
Override drawRect:
Strong. Object memory is freed at the end of the routine.
Strongly.


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

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13. Class methods are used for ___________ and the call starts with ____________.
Cocoa Touch - Media - Core Services - Core OS
Introspection - with the class method 'class'
Creating objects - or finding information relative to the class. The name of the class is the first thing in the square brackets.
id


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

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15. Is NSArray mutable?
No. Use NSMutableArray - which is a subclass of NSArray.
A rectangular area
Introspection - with the class method 'class'
A collection of collections in graph form. Can include NSArray - NSDictionary - NSNumber - NSString - NSData - and NSData.


16. What is the frame property of a UIView?

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17. What is the center property of a UIView?

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18. Talk about BOOL variables.
Cocoa Touch - Media - Core Services - Core OS
Dash - Plus sign.
Wrap it in NSValue. And remember that NSValue immutable.
NO is zero; YES is anything else.


19. How to tell whether an object is of a class or class that inherits from that class? (Write a line of code)
[Object isKindOfClass:[Classname class]]
zero/nil
Immutable. But there are many methods that take an NSString and returned a modified one. This is fast and preferable to using NSMutableString.
Getter and setter methods.


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

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21. Talk about NSString
Can handle any language because it uses Unicode.
addSubview; removeFromSubview
NSSet; no - it's immutable
At runtime.


22. What is the bounds property of a UIView?
Never!
Designated initializer.
NSUserDefaults - which stores a property list.
internal origin and size. Use this inside a view


23. All classes should have a __________________ to be called by subclasses.
No - it gets the data from the controller.
@interface JGEmailLoginEmailViewController(){ NSMutableData _receivedData; }@property (weak -nonatomic) JGAppDelegate appDelegate;@property (weak - nonatomic) IBOutlet UITextField *txtfldEmailAddress;@end
Designated initializer.
option-click; option-double-click


24. Dot notation does what?
'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.
Can handle any language because it uses Unicode.
On left side - is calling the setter - and on the right side - is calling the getter.
To zero; so pointers are nil.


25. What is the makeup of a CGSize?
Nothing happens - and nil is returned.
[Object isMemberOfClass:[Classname class]]
Two floats - for width and height
UIWindow


26. In a nutshell: how to do custom drawing?
Override drawRect:
Properties; instance variables
A framework.
Sort of - in ways that it doesn't need to know much about the controller. For example: delegation.


27. How to access the controller's top view?
Designated initializer.
self.view
for...in; don't change things inside the loop.
Argument validation.


28. What to do in Xcode for short documentation? For full documentation?
[[UIView alloc] initWithFrame]
option-click; option-double-click
constant NSString
To zero; so pointers are nil.


29. The decision on what method to call is made when?
Instance variable (ivar) or 'backing variable'
(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.
At runtime.
id; an object pointer


30. What does the controller do?
Controls how the model is presented onscreen.
[[UIView alloc] initWithFrame]
The document; possibly a database.
UIViewController.


31. Remember that it's cool to...
Controls how the model is presented onscreen.
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];
line up the colons!
Yes. The controller knows everything about the model.


32. The setters for outlets are called by _______ at this point ______________.
line up the colons!
Instance method; class method.
iOS; when the view is loaded.
[Class respondsToSelector:@selector(aMethod)]


33. What is in the model?
option-click; option-double-click
The document; possibly a database.
Strong. Object memory is freed at the end of the routine.
UIViewController.


34. How is ARC done?
Two floats - for width and height
iOS; when the view is loaded.
The compiler adds code to count references.
NSLog; %@; %d and other formatters


35. Are local pointers to objects strong or weak? So what happens at the end of the routine?
Never!
Strong. Object memory is freed at the end of the routine.
No. It's fine.
Argument validation.


36. What is used in lieu of pixels? And why?
Points - to achieve device-independence
internal origin and size. Use this inside a view
No. It's fine.
Two CGFloats for x and y


37. How about the model talking to the controller?

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38. How to see all actions - outlets - incoming/outgoing segues on a view?
Immutable. But there are many methods that take an NSString and returned a modified one. This is fast and preferable to using NSMutableString.
UIViewController.
Right-click on view - or even a subview like a button.
zero/nil


39. A _______ goes from the Controller to the View. A ________ goes from the view to the controller.
To zero; so pointers are nil.
[Object isMemberOfClass:[Classname class]]
Outlet; Action
No. It's fine.


40. Some controllers have ____________ as their views.
Cocoa Touch - Media - Core Services - Core OS
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];
Other MVC trios.
create a model


41. How to create a UIView in code?
create a model
A rectangular area
[[UIView alloc] initWithFrame]
A CGPoint and and a CGSize


42. What is the name of a property in the controller that it uses to talk to views?
Outlet; Action
the controller's minions. Gets things to the screen.
[Class respondsToSelector:@selector(aMethod)]
An outlet.


43. How to instantiate an object?
NSData
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];
Cocoa Touch - Media - Core Services - Core OS
Right-click on view - or even a subview like a button.


44. How many superviews does a view have? How many subviews?
One; zero to many
1) Create a context 2) Create paths 3) Set colors - fonts - widths 4) Stroke or fill the above-created paths.
Right-click on view - or even a subview like a button.
(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.


45. What is a reason to write our own setter?
Interface; Implementation
Argument validation.
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];
Instance variable (ivar) or 'backing variable'


46. How to add subviews in code? How to remove them?
self
addSubview; removeFromSubview
No...but it has 'a way' to notify the controller to come ask for fresh data.
Wrap it in NSValue. And remember that NSValue immutable.


47. Does a view 'own' the data it displays?
MVC - for model-view-controller
No - it gets the data from the controller.
NSSet; no - it's immutable
'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.


48. What does 'weak' mean?

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

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50. The controller is always a subclass of...?
UIViewController.
Nothing happens - and nil is returned.
Lazy instantiation.
NSObject