chap 14 to 19 - Objective C

Question 2

NSString

Answer 2

a class that holds strings.

Question 3

NSLog()

Answer 3

is an objective-C function (not a method!) the format string is actually a method of NSString.

Question 4

NSArray

Answer 4

A class that holds a list of pointers to other objects.
NSArray *datelist = [NSArray arrayWithObjects:now, tomorrow, yesterday, nil];

Question 5

NSArray methods

Answer 5

count – returns the number of items in an array.

objectAtIndex – returns the pointer that the array has stored at the index specified argument.

Question 6

fast enumeration

Answer 6

a type of loop that is extremely efficient way to walk through the items of an array.
for (NSDate *d in datelist){
NSLog(@”Here is a date: %d”, d);
}

Question 7

MSMutableArray

Answer 7

similar to an instance of NSAray but you can add and remove pointers. It is a subclass of NSArray.
[datelist addobject:now];
[datelist insertObject:yesterday atIndex:0];

Question 8

class is defined by what two files?

Answer 8

Header(interface) file – contains declarations of instance varibles and methods.

implementation file – this is where you write out steps for, or implement, each method.

Question 9

instance method

Answer 9

Begins with a dash. - (void) setDoors:(int)anInt { … }

Question 10

class method

Answer 10

Begins with a plus. +(int) wheels {
return 4;
}

Question 11

@property

Answer 11

initializes get and set methods. @property int doors;

Question 12

self

Answer 12

a pointer to the object that is running the method. It is used when an object wants to send a message to itself.

Question 13

inheritance

Answer 13

a class inherits the instance variables and methods from the parent class.

Question 14

@synthesize

Answer 14

sets get and set methods in the implementation file.
#import “Employee.h”
@implementation Employee
@synthesize employeeID;
@end

Question 15

super

Answer 15

the super directive says, run this method, but start the search for its implementation at my superclass.

Question 16

object instance variables

Answer 16

points to another object and describes a relationship between two objects.

Question 17

object instance three catagories

Answer 17

Object-type attributes – a pointer to a value-like object like NSString.

To-one relationships – a pointer to a single complex object.

To-many relationships – a pointer to an instance of a collection class like MSMutableArray.

Question 18

object ownership

Answer 18

when an object has an object instance variable, the object with the pointer is said to own the object that is being pointed to. When an object has zero owners it deallocates itself.

Question 19

ARC, Automatic Reference counting

Answer 19

controls the owner count of each object. added in xcode 4.2