1. Objective-C Survives
Shumpei Akai

2. Objective-C
• Objective-C == C + (Smalltalk
)OOP
• C++ == C + Chaos

3. Objective-C
• C
• Objective-C++
•
• Ruby
• OK
•

4. • 3
•
•
•
• C

5. • Objective-C
• Cocoa

6. •
• gcc
• clang (LLVM )
• “.m”

7. •
• mac XCode
•
• Cocoa (mac) / Cocoa Touch (iOS)
• GNUStep ( )

8. Objective-C
• 1983: Brad Cox (C++ )
• 1988: NeXT ( )
• 1995: NeXT
• 1996: Apple NeXT
• 2001: Mac OS X
• 2007: Objective-C 2.0

10. •
//
[str length]
// 1
[array objectAtIndex:0]
// 2
[array insertObject: obj atIndex: 2]

11. •
• Ruby Lisp
• “insertObject:atIndex:”
• “objectAtIndex:”

12. •
• stringByAppendingString:
•
• setObject:forKey:
•

13. •
•
•
•

15. id :

17. ※
Objective-C

18. • ClassName* OK
•
• id
•

19. nil
• (id )
• null
• nil
• 0/NULL/nil
•

20. NSMutableArray *array =
[NSMutableArray arrayWithObjects: @"one",
@"two”, nil];
NSArray *newAdditions =
[NSArray arrayWithObjects: @"3", @"4", @"5",
nil];
[arry addObjectsFromArray: newAdditions];

21. BOOL
•
• C++/C99
• YES/NO

22. • (.h)
@interface ClassName : SuperClassName {
id instanceVariable;
}
- (void)instanceMethod;
+ (id)classmethod;
@end

23. • (.m)
@implementation ClassName
- (void)instanceMethod{
//
}
+ (id)classmethod{
//
}
@end

24. • (java.lang.Object
)
•
• Cocoa NSObject
•

25. • java
•
• 2 prefix
• apple NS (== NeXT Step)
•

26. • - (void)instanceMethodWithArg:(id)arg{ }
• Java
• self
•

27. • obj->instanceVar
• ( )
• self
• @public, @protected, @private
• @protected ( )

28. • + (void)classMethodWithArg:(id)arg{ }
•
• [ClassName methodName]

29. • [ClassName class]
•
• ==
• [ClassName foo] == [[ClassName class] foo]

30. •
• static

31. •

32. +alloc +allocWithZone:
•
• Cocoa
•
•

33. - init
• [[NSObject alloc] init]
•
• init
-(id) init{
self = [super init];
if(self){
//
}
return self;
}

34. alloc init
•
•
• ?
•
•

35. Cocoa
•
•
• free retain(+1)
• release(-1)
• 0

36. • caller
• alloc,new,copy,mutableCopy
• +1
-(void) doFoo{
NSString* str=[[NSString alloc] init] ;
//
[str release]; //
}

37. •
•
- (void)doBarWithArray:(NSArray*)ary{
id obj=[ary objectAtIndex:0];
//ary obj release
}

38. retain
• /
retain
•
- (void)doBarWithArray:(NSArray*)ary{
self->ary = [ary retain];
}

39. release
• release
• nil
- (void)didReceiveMemoryWarning{
[self->data release];
self->data = nil; //data free
}

40. • caller
• caller free
-(NSString*) makeString{
return [[NSString alloc] init] ;
//caller release
}
-(NSString*) makeString{
return [[[NSString alloc] init] release];
//return
}

41. autorelease
• release
• release
• obj
-(NSString*) makeString{
return [[[NSString alloc] init] autorelease];
//
}

42. AutoreleasePool
• autorelease
• => release
•
- (void)foo{
NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
//do something
[pool release];
}

43. dealloc
• 0
• obj
release
-(void) dealloc{
[self->str release];
[self->ary release];
[super dealloc];
}

44. •
• Cocoa
•
• retain
• retain

45. • Java interface
• optional OK
@protocol HogeProtocol <SuperProtocol>
-(BOOL)isCharactor;
-(BOOL)isDisplay;
-(void)start;
-(void)abort;
-(BOOL)step;
@optional
-(void)callbackWithData:(NSData*)data;
@end

46. • Java
• id<FooProtocol> : FooProtocol
• BarClass<FooProtocol>* : BarClass
FooProtocol

47. •
@implementation ClassName(CategoryName)
- (void)addingMethod{
//
}
@end

48. • obj.proptyName
•
@interface ClassName : NSObject {
}
@property (nonatomic,retain) id prop; @implementation ClassName
@end @synthesize prop;
@end

49. • NSObject
• ?
• - (BOOL)respondsToSelector:(SEL)aSelector
•
• - (id)performSelector:(SEL)aSelector
• - (id)performSelector:(SEL)aSelector withObject:(id)anObject
• - (id)performSelector:(SEL)aSelector withObject:(id)anObject
withObject:(id)anotherObject

50. (cont.)
•
• - (IMP)methodForSelector:(SEL)aSelector
•
• Class NSClassFromString(NSString *aClassName);

51. •
• NSString
• @”hoge”;
• NSMutableString
• Cocoa mutable immutable

52. • NSArray/NSMutableArray
• :
• [NSMutableArray arrayWithObjects:@”one”,
@”two”,nil]
• Cocoa
• nil

53. /
•
• NSDictionary/NSMutableDictionary
•
• NSSet/NSMutableSet

54. • NSValue
• C
• NSNumber
•
• 1
• [NSNumber numberWithBool:YES]
• [NSNumber numberWithInt:0]
• [NSNumber numberWithDouble:1.0]

55. Objective-C
•C
•
•
• C

56. Objective-C
• OOP
•

57. Objective-C
• OS
•
•
• /

58. •
• delegate
• target/action
• ARC(Automatic Reference Counting)
• Blocks
• Grand Central Dispatch