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. Some controllers have ____________ as their views.
Override drawRect:
Other MVC trios.
Can handle any language because it uses Unicode.
Strong. Object memory is freed at the end of the routine.


2. How to force a redraw of a custom area?
Argument validation.
The document; possibly a database.
Call setNeedsDisplay:
Two floats - for width and height


3. In a nutshell: how to do custom drawing?
Controls how the model is presented onscreen.
Lazy instantiation.
NSSet; no - it's immutable
Override drawRect:


4. What is the name of a property in the controller that it uses to talk to views?
'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.
NSSet; no - it's immutable
The runtime system asks the object what its class is.
An outlet.


5. Show a private interface section.
NSArray; no - it's immutable.
Import / handle multiple inclusion.
@interface JGEmailLoginEmailViewController(){ NSMutableData _receivedData; }@property (weak -nonatomic) JGAppDelegate appDelegate;@property (weak - nonatomic) IBOutlet UITextField *txtfldEmailAddress;@end
Yes. As much as it wants.


6. What about the view talking to the controller?

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7. What about controller talking to the model?
[[UIView alloc] initWithFrame]
iOS; when the view is loaded.
Yes. The controller knows everything about the model.
On left side - is calling the setter - and on the right side - is calling the getter.


8. Is NSString mutable or not?
Sort of - in ways that it doesn't need to know much about the controller. For example: delegation.
Call setNeedsDisplay:
Immutable. But there are many methods that take an NSString and returned a modified one. This is fast and preferable to using NSMutableString.
Lazy instantiation.


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

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10. Talk about BOOL variables.
'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.'
zero/nil
Call setNeedsDisplay:
NO is zero; YES is anything else.


11. What is the base class for most objects in the iOS SDK?
At runtime.
A collection of collections in graph form. Can include NSArray - NSDictionary - NSNumber - NSString - NSData - and NSData.
NSObject
Getter and setter methods.


12. What is a property list?
A collection of collections in graph form. Can include NSArray - NSDictionary - NSNumber - NSString - NSData - and NSData.
Two floats - for width and height
NSData
[Class respondsToSelector:@selector(aMethod)]


13. Class methods are used for ___________ and the call starts with ____________.
Creating objects - or finding information relative to the class. The name of the class is the first thing in the square brackets.
Class XX = [Object class]
Nothing happens - and nil is returned.
My rectangle in my superview's coordinate space


14. Classes cannot have _________ or ___________.
1) Create a context 2) Create paths 3) Set colors - fonts - widths 4) Stroke or fill the above-created paths.
Never!
Instance variable (ivar) or 'backing variable'
Properties; instance variables


15. How to access the controller's top view?
Never!
Outlet; Action
Cocoa Touch - Media - Core Services - Core OS
self.view


16. Objects in an array: are the pointed to strongly or weakly?
NSLog; %@; %d and other formatters
A CGPoint and and a CGSize
Strongly.
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];


17. The controller is always a subclass of...?
Strong. Object memory is freed at the end of the routine.
[Class respondsToSelector:@selector(aMethod)]
UIViewController.
option-click; option-double-click


18. What is a reason to write our own setter?
self
Argument validation.
A CGPoint and and a CGSize
Introspection - with the class method 'class'


19. When happens when you send a message to nil?
NO is zero; YES is anything else.
[Class respondsToSelector:@selector(aMethod)]
Nothing happens - and nil is returned.
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];


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

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21. How are local variables initialized in iOS 5?
1) Create a context 2) Create paths 3) Set colors - fonts - widths 4) Stroke or fill the above-created paths.
To zero; so pointers are nil.
NSLog; %@; %d and other formatters
A CGPoint and and a CGSize


22. Instance methods start with a ______ and class methods start with a ______.
id
Dash - Plus sign.
line up the colons!
NSLog; %@; %d and other formatters


23. 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.
Can handle any language because it uses Unicode.
Never!
No - it gets the data from the controller.


24. How to instantiate an object?
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.
A rectangular area
A framework.
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];


25. Is NSArray mutable?
Never!
No. Use NSMutableArray - which is a subclass of NSArray.
Override drawRect:
self.view


26. If I need to convert a number to an object - use __________
NSNumber. For example numberWithDouble: and doubleValue:
Yes. The controller knows everything about the model.
A rectangular area
option-click; option-double-click


27. How to see all actions - outlets - incoming/outgoing segues on a view?
On left side - is calling the setter - and on the right side - is calling the getter.
No - it gets the data from the controller.
Right-click on view - or even a subview like a button.
@interface JGEmailLoginEmailViewController(){ NSMutableData _receivedData; }@property (weak -nonatomic) JGAppDelegate appDelegate;@property (weak - nonatomic) IBOutlet UITextField *txtfldEmailAddress;@end


28. You can send a message to a...
On left side - is calling the setter - and on the right side - is calling the getter.
Argument validation.
constant NSString
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.


29. What is the iOS term for a library?
A framework.
Introspection - with the class method 'class'
Designated initializer.
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.


30. Why are properties good?
NO is zero; YES is anything else.
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.
'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.


31. The view is...

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32. A _______ goes from the Controller to the View. A ________ goes from the view to the controller.
Strongly.
MVC - for model-view-controller
Outlet; Action
NO is zero; YES is anything else.


33. What is at the top of the view hierarchy?
To zero; so pointers are nil.
Never!
Strongly.
UIWindow


34. How many superviews does a view have? How many subviews?
Getter and setter methods.
One; zero to many
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.
NSSet; no - it's immutable


35. The decision on what method to call is made when?
Action
addSubview; removeFromSubview
At runtime.
Never!


36. A property is just the combination of _______.
Getter and setter methods.
On left side - is calling the setter - and on the right side - is calling the getter.
create a model
Outlet; Action


37. There is no difference between _____ and _______ at runtime.
My rectangle in my superview's coordinate space
An outlet.
Two CGFloats for x and y
id; an object pointer


38. How can I save user information between launches of my app?
Yes. As much as it wants.
Designated initializer.
NSUserDefaults - which stores a property list.
NSSet; no - it's immutable


39. What is the makeup of a CGSize?
Two floats - for width and height
No. Use NSMutableArray - which is a subclass of NSArray.
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.
Cocoa Touch - Media - Core Services - Core OS


40. ______ is a pointer
self
iOS; when the view is loaded.
A CGPoint and and a CGSize
NSData


41. What is used in lieu of pixels? And why?
internal origin and size. Use this inside a view
An outlet.
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];
Points - to achieve device-independence


42. Dot notation does what?
Cocoa Touch - Media - Core Services - Core OS
Action
On left side - is calling the setter - and on the right side - is calling the getter.
Outlet; Action


43. ________ implements the getter and setter. But we can always__________
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.
@synthesize; write our own getter and/or setter.
'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.
line up the colons!


44. Can the controller talking to the view?
create a model
Yes. As much as it wants.
Nothing happens - and nil is returned.
At runtime.


45. ______ is a pointer to any object.
[Object isKindOfClass:[Classname class]]
Yes. As much as it wants.
id
Override drawRect:


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

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

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48. What is the makeup of a CGPoint?
To zero; so pointers are nil.
One; zero to many
Call setNeedsDisplay:
Two CGFloats for x and y


49. What is the center property of a UIView?

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50. Are local pointers to objects strong or weak? So what happens at the end of the routine?
zero/nil
A rectangular area
Strong. Object memory is freed at the end of the routine.
Never!