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. 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.
In the getter! This is called lazy instantiation.
Introspection - with the class method 'class'
NSLog; %@; %d and other formatters

2. How to see all actions - outlets - incoming/outgoing segues on a view?
Right-click on view - or even a subview like a button.
id; an object pointer
Properties; instance variables
Two floats - for width and height

3. What is the iOS term for a library?
Sort of - in ways that it doesn't need to know much about the controller. For example: delegation.
Action
A framework.
Instance variable (ivar) or 'backing variable'

4. What does the controller do?
Controls how the model is presented onscreen.
Properties; instance variables
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];
NSObject

5. How are local variables initialized in iOS 5?
Override drawRect:
To zero; so pointers are nil.
NSSet; no - it's immutable
NSNumber. For example numberWithDouble: and doubleValue:

6. All classes should have a __________________ to be called by subclasses.
The compiler adds code to count references.
UIViewController.
UIWindow
Designated initializer.

7. ______ is a pointer to any object.
id
Center of the frame - which is in the superview's coordinate system
Never!
id; an object pointer

8. Instance methods start with a ______ and class methods start with a ______.
for...in; don't change things inside the loop.
Dash - Plus sign.
Yes. As much as it wants.
line up the colons!

9. Talk about NSString
NSLog; %@; %d and other formatters
[Object isKindOfClass:[Classname class]]
Yes. As much as it wants.
Can handle any language because it uses Unicode.

10. What is at the top of the view hierarchy?
addSubview; removeFromSubview
UIWindow
@synthesize; write our own getter and/or setter.
Yes. As much as it wants.

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

12. What is the frame property of a UIView?

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

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

15. When happens when you send a message to nil?
Controls how the model is presented onscreen.
Yes. The controller knows everything about the model.
Nothing happens - and nil is returned.
At runtime.

16. A _______ goes from the Controller to the View. A ________ goes from the view to the controller.
Strong. Object memory is freed at the end of the routine.
the controller's minions. Gets things to the screen.
Outlet; Action
Properties; instance variables

17. A _______ is how a view notifies the controller of something - for example - a button press.
Action
At runtime.
A rectangular area
id

18. What is the center property of a UIView?

19. If I need to convert a number to an object - use __________
NSNumber. For example numberWithDouble: and doubleValue:
Designated initializer.
No. It's fine.
Can handle any language because it uses Unicode.

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

21. Does a view 'own' the data it displays?
No - it gets the data from the controller.
Two floats - for width and height
Outlet; Action
NO is zero; YES is anything else.

22. In a nutshell: how to do custom drawing?
'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.
On left side - is calling the setter - and on the right side - is calling the getter.
Override drawRect:
No...but it has 'a way' to notify the controller to come ask for fresh data.

23. What is the bounds property of a UIView?
internal origin and size. Use this inside a view
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.
Strongly.
No - it gets the data from the controller.

24. The decision on what method to call is made when?
Class XX = [Object class]
At runtime.
Other MVC trios.
One; zero to many

25. The view is...

26. Remember that it's cool to...
line up the colons!
NO is zero; YES is anything else.
NSUserDefaults - which stores a property list.
[Class respondsToSelector:@selector(aMethod)]

27. A property is just the combination of _______.
Getter and setter methods.
UIWindow
Two floats - for width and height
Sort of - in ways that it doesn't need to know much about the controller. For example: delegation.

28. When is it OK to call drawRect: directly?
Designated initializer.
Never!
iOS; when the view is loaded.
Import / handle multiple inclusion.

29. How many superviews does a view have? How many subviews?
UIViewController.
No. It's fine.
UIWindow
One; zero to many

30. Some controllers have ____________ as their views.
Other MVC trios.
create a model
constant NSString
'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. How to add subviews in code? How to remove them?
addSubview; removeFromSubview
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];
NO is zero; YES is anything else.
NSData

32. All properties are initialized to _____
Call setNeedsDisplay:
A framework.
zero/nil
Dash - Plus sign.

33. What is an example of a reason to write a getter?
Instance variable (ivar) or 'backing variable'
My rectangle in my superview's coordinate space
Lazy instantiation.
(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.

34. You can send a message to a...
Center of the frame - which is in the superview's coordinate system
Lazy instantiation.
Call setNeedsDisplay:
constant NSString

35. What is in the model?
Two CGFloats for x and y
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.
Right-click on view - or even a subview like a button.

36. What is a property list?
A collection of collections in graph form. Can include NSArray - NSDictionary - NSNumber - NSString - NSData - and NSData.
The document; possibly a database.
The compiler adds code to count references.
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.

37. What if I want to put a scalar into an NSArray or NSSet?
Instance variable (ivar) or 'backing variable'
Wrap it in NSValue. And remember that NSValue immutable.
Right-click on view - or even a subview like a button.
Two floats - for width and height

38. How to tell whether an object implements a particular method? (A line of code)
[Class respondsToSelector:@selector(aMethod)]
Instance variable (ivar) or 'backing variable'
Interface; Implementation
On left side - is calling the setter - and on the right side - is calling the getter.

39. 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]]
Immutable. But there are many methods that take an NSString and returned a modified one. This is fast and preferable to using NSMutableString.
(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.
UIViewController.

40. 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.
Instance method; class method.
Never!
Interface; Implementation

41. How can I save user information between launches of my app?
option-click; option-double-click
The document; possibly a database.
NSData
NSUserDefaults - which stores a property list.

42. What is the fundamental design pattern of iOS development?
NSSet; no - it's immutable
UIViewController.
Other MVC trios.
MVC - for model-view-controller

43. How is ARC done?
Outlet; Action
The compiler adds code to count references.
NSUserDefaults - which stores a property list.
Lazy instantiation.

44. The basic steps in custom drawing.
Argument validation.
The compiler adds code to count references.
1) Create a context 2) Create paths 3) Set colors - fonts - widths 4) Stroke or fill the above-created paths.
(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. Dot notation does what?
A rectangular area
zero/nil
On left side - is calling the setter - and on the right side - is calling the getter.
iOS; when the view is loaded.

46. What is the makeup of a CGPoint?
On left side - is calling the setter - and on the right side - is calling the getter.
self.view
MVC - for model-view-controller
Two CGFloats for x and y

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

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

49. If a method starts with a dash - it's a ___________. If it starts with a plus sign - it's a ______________.
My rectangle in my superview's coordinate space
Instance method; class method.
[Object isKindOfClass:[Classname class]]
create a model

50. How can I find out the class of any object? Give a line of code.
Class XX = [Object class]
1.) Ask another object to do it - e.g. with mutableCopy. 2.) Call a class method - 3.) [[Classname alloc] init];
Yes. The controller knows everything about the model.
An outlet.