Objective-C 入门教程
来源：互联网 发布：windows组管理策略 编辑：程序博客网 时间：2024/05/19 06:49
大纲 § #import <stdio.h> § § int main( int argc, const char *argv[] ) { § printf( "hello world/n" ); § return 0; } hello world § #import <Foundation/NSObject.h> § § @interface Fraction: NSObject { § int numerator; § int denominator; § } § § -(void) print; § -(void) setNumerator: (int) d; § -(void) setDenominator: (int) d; § -(int) numerator; § -(int) denominator; § @end § #import "Fraction.h" § #import <stdio.h> § § @implementation Fraction § -(void) print { § printf( "%i/%i", numerator, denominator ); § } § § -(void) setNumerator: (int) n { § numerator = n; § } § § -(void) setDenominator: (int) d { § denominator = d; § } § § -(int) denominator { § return denominator; § } § § -(int) numerator { § return numerator; § } @end § #import <stdio.h> § #import "Fraction.h" § § int main( int argc, const char *argv[] ) { § // create a new instance § Fraction *frac = [[Fraction alloc] init]; § § // set the values § [frac setNumerator: 1]; § [frac setDenominator: 3]; § § // print it § printf( "The fraction is: " ); § [frac print]; § printf( "/n" ); § § // free memory § [frac release]; § § return 0; } The fraction is: 1/3 § ... § -(void) setNumerator: (int) n andDenominator: (int) d; ... § ... § -(void) setNumerator: (int) n andDenominator: (int) d { § numerator = n; § denominator = d; § } ... § #import <stdio.h> § #import "Fraction.h" § § int main( int argc, const char *argv[] ) { § // create a new instance § Fraction *frac = [[Fraction alloc] init]; § Fraction *frac2 = [[Fraction alloc] init]; § § // set the values § [frac setNumerator: 1]; § [frac setDenominator: 3]; § § // combined set § [frac2 setNumerator: 1 andDenominator: 5]; § § // print it § printf( "The fraction is: " ); § [frac print]; § printf( "/n" ); § § // print it § printf( "Fraction 2 is: " ); § [frac2 print]; § printf( "/n" ); § § // free memory § [frac release]; § [frac2 release]; § § return 0; } § The fraction is: 1/3 Fraction 2 is: 1/5 § ... § -(Fraction*) initWithNumerator: (int) n denominator: (int) d; ... § ... § -(Fraction*) initWithNumerator: (int) n denominator: (int) d { § self = [super init]; § § if ( self ) { § [self setNumerator: n andDenominator: d]; § } § § return self; § } ... § #import <stdio.h> § #import "Fraction.h" § § int main( int argc, const char *argv[] ) { § // create a new instance § Fraction *frac = [[Fraction alloc] init]; § Fraction *frac2 = [[Fraction alloc] init]; § Fraction *frac3 = [[Fraction alloc] initWithNumerator: 3 denominator: 10]; § § // set the values § [frac setNumerator: 1]; § [frac setDenominator: 3]; § § // combined set § [frac2 setNumerator: 1 andDenominator: 5]; § § // print it § printf( "The fraction is: " ); § [frac print]; § printf( "/n" ); § § printf( "Fraction 2 is: " ); § [frac2 print]; § printf( "/n" ); § § printf( "Fraction 3 is: " ); § [frac3 print]; § printf( "/n" ); § § // free memory § [frac release]; § [frac2 release]; § [frac3 release]; § § return 0; } § The fraction is: 1/3 § Fraction 2 is: 1/5 Fraction 3 is: 3/10 § #import <Foundation/NSObject.h> § § @interface Access: NSObject { § @public § int publicVar; § @private § int privateVar; § int privateVar2; § @protected § int protectedVar; § } @end § #import "Access.h" § § @implementation Access @end § #import "Access.h" § #import <stdio.h> § § int main( int argc, const char *argv[] ) { § Access *a = [[Access alloc] init]; § § // works § a->publicVar = 5; § printf( "public var: %i/n", a->publicVar ); § § // doesn't compile § //a->privateVar = 10; § //printf( "private var: %i/n", a->privateVar ); § § [a release]; § return 0; } public var: 5 § #import <Foundation/NSObject.h> § § static int count; § § @interface ClassA: NSObject § +(int) initCount; § +(void) initialize; @end § #import "ClassA.h" § § @implementation ClassA § -(id) init { § self = [super init]; § count++; § return self; § } § § +(int) initCount { § return count; § } § § +(void) initialize { § count = 0; § } @end § #import "ClassA.h" § #import <stdio.h> § § int main( int argc, const char *argv[] ) { § ClassA *c1 = [[ClassA alloc] init]; § ClassA *c2 = [[ClassA alloc] init]; § § // print count § printf( "ClassA count: %i/n", [ClassA initCount] ); § § ClassA *c3 = [[ClassA alloc] init]; § § // print count again § printf( "ClassA count: %i/n", [ClassA initCount] ); § § [c1 release]; § [c2 release]; § [c3 release]; § § return 0; } § ClassA count: 2 ClassA count: 3 § #import <Foundation/NSException.h> § § @interface CupWarningException: NSException @end § #import "CupWarningException.h" § § @implementation CupWarningException @end § #import <Foundation/NSException.h> § § @interface CupOverflowException: NSException @end § #import "CupOverflowException.h" § § @implementation CupOverflowException @end § #import <Foundation/NSObject.h> § § @interface Cup: NSObject { § int level; § } § § -(int) level; § -(void) setLevel: (int) l; § -(void) fill; § -(void) empty; § -(void) print; @end § #import "Cup.h" § #import "CupOverflowException.h" § #import "CupWarningException.h" § #import <Foundation/NSException.h> § #import <Foundation/NSString.h> § § @implementation Cup § -(id) init { § self = [super init]; § § if ( self ) { § [self setLevel: 0]; § } § § return self; § } § § -(int) level { § return level; § } § § -(void) setLevel: (int) l { § level = l; § § if ( level > 100 ) { § // throw overflow § NSException *e = [CupOverflowException § exceptionWithName: @"CupOverflowException" § reason: @"The level is above 100" § userInfo: nil]; § @throw e; § } else if ( level >= 50 ) { § // throw warning § NSException *e = [CupWarningException § exceptionWithName: @"CupWarningException" § reason: @"The level is above or at 50" § userInfo: nil]; § @throw e; § } else if ( level < 0 ) { § // throw exception § NSException *e = [NSException § exceptionWithName: @"CupUnderflowException" § reason: @"The level is below 0" § userInfo: nil]; § @throw e; § } § } § § -(void) fill { § [self setLevel: level + 10]; § } § § -(void) empty { § [self setLevel: level - 10]; § } § § -(void) print { § printf( "Cup level is: %i/n", level ); § } @end § #import "Cup.h" § #import "CupOverflowException.h" § #import "CupWarningException.h" § #import <Foundation/NSString.h> § #import <Foundation/NSException.h> § #import <Foundation/NSAutoreleasePool.h> § #import <stdio.h> § § int main( int argc, const char *argv[] ) { § NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; § Cup *cup = [[Cup alloc] init]; § int i; § § // this will work § for ( i = 0; i < 4; i++ ) { § [cup fill]; § [cup print]; § } § § // this will throw exceptions § for ( i = 0; i < 7; i++ ) { § @try { § [cup fill]; § } @catch ( CupWarningException *e ) { § printf( "%s: ", [[e name] cString] ); § } @catch ( CupOverflowException *e ) { § printf( "%s: ", [[e name] cString] ); § } @finally { § [cup print]; § } § } § § // throw a generic exception § @try { § [cup setLevel: -1]; § } @catch ( NSException *e ) { § printf( "%s: %s/n", [[e name] cString], [[e reason] cString] ); § } § § // free memory § [cup release]; § [pool release]; } § Cup level is: 10 § Cup level is: 20 § Cup level is: 30 § Cup level is: 40 § CupWarningException: Cup level is: 50 § CupWarningException: Cup level is: 60 § CupWarningException: Cup level is: 70 § CupWarningException: Cup level is: 80 § CupWarningException: Cup level is: 90 § CupWarningException: Cup level is: 100 § CupOverflowException: Cup level is: 110 CupUnderflowException: The level is below 0 § #import <Foundation/NSObject.h> § § @interface Fraction: NSObject { § int numerator; § int denominator; § } § § -(Fraction*) initWithNumerator: (int) n denominator: (int) d; § -(void) print; § -(void) setNumerator: (int) d; § -(void) setDenominator: (int) d; § -(void) setNumerator: (int) n andDenominator: (int) d; § -(int) numerator; § -(int) denominator; @end § #import "Fraction.h" § #import <stdio.h> § § @implementation Fraction § -(Fraction*) initWithNumerator: (int) n denominator: (int) d { § self = [super init]; § § if ( self ) { § [self setNumerator: n andDenominator: d]; § } § § return self; § } § § -(void) print { § printf( "%i / %i", numerator, denominator ); § } § § -(void) setNumerator: (int) n { § numerator = n; § } § § -(void) setDenominator: (int) d { § denominator = d; § } § § -(void) setNumerator: (int) n andDenominator: (int) d { § numerator = n; § denominator = d; § } § § -(int) denominator { § return denominator; § } § § -(int) numerator { § return numerator; § } @end § #import <Foundation/NSObject.h> § § @interface Complex: NSObject { § double real; § double imaginary; § } § § -(Complex*) initWithReal: (double) r andImaginary: (double) i; § -(void) setReal: (double) r; § -(void) setImaginary: (double) i; § -(void) setReal: (double) r andImaginary: (double) i; § -(double) real; § -(double) imaginary; § -(void) print; § @end § #import "Complex.h" § #import <stdio.h> § § @implementation Complex § -(Complex*) initWithReal: (double) r andImaginary: (double) i { § self = [super init]; § § if ( self ) { § [self setReal: r andImaginary: i]; § } § § return self; § } § § -(void) setReal: (double) r { § real = r; § } § § -(void) setImaginary: (double) i { § imaginary = i; § } § § -(void) setReal: (double) r andImaginary: (double) i { § real = r; § imaginary = i; § } § § -(double) real { § return real; § } § § -(double) imaginary { § return imaginary; § } § § -(void) print { § printf( "%_f + %_fi", real, imaginary ); § } § @end § #import <stdio.h> § #import "Fraction.h" § #import "Complex.h" § § int main( int argc, const char *argv[] ) { § // create a new instance § Fraction *frac = [[Fraction alloc] initWithNumerator: 1 denominator: 10]; § Complex *comp = [[Complex alloc] initWithReal: 10 andImaginary: 15]; § id number; § § // print fraction § number = frac; § printf( "The fraction is: " ); § [number print]; § printf( "/n" ); § § // print complex § number = comp; § printf( "The complex number is: " ); § [number print]; § printf( "/n" ); § § // free memory § [frac release]; § [comp release]; § § return 0; } § The fraction is: 1 / 10 The complex number is: 10.000000 + 15.000000i § #import <Foundation/NSObject.h> § § @interface Rectangle: NSObject { § int width; § int height; § } § § -(Rectangle*) initWithWidth: (int) w height: (int) h; § -(void) setWidth: (int) w; § -(void) setHeight: (int) h; § -(void) setWidth: (int) w height: (int) h; § -(int) width; § -(int) height; § -(void) print; @end § #import "Rectangle.h" § #import <stdio.h> § § @implementation Rectangle § -(Rectangle*) initWithWidth: (int) w height: (int) h { § self = [super init]; § § if ( self ) { § [self setWidth: w height: h]; § } § § return self; § } § § -(void) setWidth: (int) w { § width = w; § } § § -(void) setHeight: (int) h { § height = h; § } § § -(void) setWidth: (int) w height: (int) h { § width = w; § height = h; § } § § -(int) width { § return width; § } § § -(int) height { § return height; § } § § -(void) print { § printf( "width = %i, height = %i", width, height ); § } @end § #import "Rectangle.h" § § @interface Square: Rectangle § -(Square*) initWithSize: (int) s; § -(void) setSize: (int) s; § -(int) size; @end § #import "Square.h" § § @implementation Square § -(Square*) initWithSize: (int) s { § self = [super init]; § § if ( self ) { § [self setSize: s]; § } § § return self; § } § § -(void) setSize: (int) s { § width = s; § height = s; § } § § -(int) size { § return width; § } § § -(void) setWidth: (int) w { § [self setSize: w]; § } § § -(void) setHeight: (int) h { § [self setSize: h]; § } @end § #import "Square.h" § #import "Rectangle.h" § #import <stdio.h> § § int main( int argc, const char *argv[] ) { § Rectangle *rec = [[Rectangle alloc] initWithWidth: 10 height: 20]; § Square *sq = [[Square alloc] initWithSize: 15]; § § // print em § printf( "Rectangle: " ); § [rec print]; § printf( "/n" ); § § printf( "Square: " ); § [sq print]; § printf( "/n" ); § § // update square § [sq setWidth: 20]; § printf( "Square after change: " ); § [sq print]; § printf( "/n" ); § § // free memory § [rec release]; § [sq release]; § § return 0; } § Rectangle: width = 10, height = 20 § Square: width = 15, height = 15 Square after change: width = 20, height = 20 -(BOOL) isKindOfClass: classObj is object a descendent or member of classObj -(BOOL) isMemberOfClass: classObj is object a member of classObj -(BOOL) respondsToSelector: selector does the object have a method named specifiec by the selector +(BOOL) instancesRespondToSelector: selector does an object created by this class have the ability to respond to the specified selector -(id) performSelector: selector invoke the specified selector on the object § #import "Square.h" § #import "Rectangle.h" § #import <stdio.h> § § int main( int argc, const char *argv[] ) { § Rectangle *rec = [[Rectangle alloc] initWithWidth: 10 height: 20]; § Square *sq = [[Square alloc] initWithSize: 15]; § § // isMemberOfClass § § // true § if ( [sq isMemberOfClass: [Square class]] == YES ) { § printf( "square is a member of square class/n" ); § } § § // false § if ( [sq isMemberOfClass: [Rectangle class]] == YES ) { § printf( "square is a member of rectangle class/n" ); § } § § // false § if ( [sq isMemberOfClass: [NSObject class]] == YES ) { § printf( "square is a member of object class/n" ); § } § § // isKindOfClass § § // true § if ( [sq isKindOfClass: [Square class]] == YES ) { § printf( "square is a kind of square class/n" ); § } § § // true § if ( [sq isKindOfClass: [Rectangle class]] == YES ) { § printf( "square is a kind of rectangle class/n" ); § } § § // true § if ( [sq isKindOfClass: [NSObject class]] == YES ) { § printf( "square is a kind of object class/n" ); § } § § // respondsToSelector § § // true § if ( [sq respondsToSelector: @selector( setSize: )] == YES ) { § printf( "square responds to setSize: method/n" ); § } § § // false § if ( [sq respondsToSelector: @selector( nonExistant )] == YES ) { § printf( "square responds to nonExistant method/n" ); § } § § // true § if ( [Square respondsToSelector: @selector( alloc )] == YES ) { § printf( "square class responds to alloc method/n" ); § } § § // instancesRespondToSelector § § // false § if ( [Rectangle instancesRespondToSelector: @selector( setSize: )] == YES ) { § printf( "rectangle instance responds to setSize: method/n" ); § } § § // true § if ( [Square instancesRespondToSelector: @selector( setSize: )] == YES ) { § printf( "square instance responds to setSize: method/n" ); § } § § // free memory § [rec release]; § [sq release]; § § return 0; } § square is a member of square class § square is a kind of square class § square is a kind of rectangle class § square is a kind of object class § square responds to setSize: method § square class responds to alloc method square instance responds to setSize: method § #import "Fraction.h" § § @interface Fraction (Math) § -(Fraction*) add: (Fraction*) f; § -(Fraction*) mul: (Fraction*) f; § -(Fraction*) div: (Fraction*) f; § -(Fraction*) sub: (Fraction*) f; @end § #import "FractionMath.h" § § @implementation Fraction (Math) § -(Fraction*) add: (Fraction*) f { § return [[Fraction alloc] initWithNumerator: numerator * [f denominator] + § denominator * [f numerator] § denominator: denominator * [f denominator]]; § } § § -(Fraction*) mul: (Fraction*) f { § return [[Fraction alloc] initWithNumerator: numerator * [f numerator] § denominator: denominator * [f denominator]]; § § } § § -(Fraction*) div: (Fraction*) f { § return [[Fraction alloc] initWithNumerator: numerator * [f denominator] § denominator: denominator * [f numerator]]; § } § § -(Fraction*) sub: (Fraction*) f { § return [[Fraction alloc] initWithNumerator: numerator * [f denominator] - § denominator * [f numerator] § denominator: denominator * [f denominator]]; § } @end § #import <stdio.h> § #import "Fraction.h" § #import "FractionMath.h" § § int main( int argc, const char *argv[] ) { § // create a new instance § Fraction *frac1 = [[Fraction alloc] initWithNumerator: 1 denominator: 3]; § Fraction *frac2 = [[Fraction alloc] initWithNumerator: 2 denominator: 5]; § Fraction *frac3 = [frac1 mul: frac2]; § § // print it § [frac1 print]; § printf( " * " ); § [frac2 print]; § printf( " = " ); § [frac3 print]; § printf( "/n" ); § § // free memory § [frac1 release]; § [frac2 release]; § [frac3 release]; § § return 0; } 1/3 * 2/5 = 2/15 § #import <Foundation/NSObject.h> § § @interface MyClass: NSObject § -(void) publicMethod; @end § #import "MyClass.h" § #import <stdio.h> § § @implementation MyClass § -(void) publicMethod { § printf( "public method/n" ); § } § @end § § // private methods § @interface MyClass (Private) § -(void) privateMethod; § @end § § @implementation MyClass (Private) § -(void) privateMethod { § printf( "private method/n" ); § } @end § #import "MyClass.h" § § int main( int argc, const char *argv[] ) { § MyClass *obj = [[MyClass alloc] init]; § § // this compiles § [obj publicMethod]; § § // this throws errors when compiling § //[obj privateMethod]; § § // free memory § [obj release]; § § return 0; } public method § #import "Fraction.h" § § @interface FractionB: Fraction § -(void) print; § @end § #import "FractionB.h" § #import <stdio.h> § § @implementation FractionB § -(void) print { § printf( "(%i/%i)", numerator, denominator ); § } @end § #import <stdio.h> § #import "Fraction.h" § #import "FractionB.h" § § int main( int argc, const char *argv[] ) { § Fraction *frac = [[Fraction alloc] initWithNumerator: 3 denominator: 10]; § § // print it § printf( "The fraction is: " ); § [frac print]; § printf( "/n" ); § § // make FractionB pose as Fraction § [FractionB poseAsClass: [Fraction class]]; § § Fraction *frac2 = [[Fraction alloc] initWithNumerator: 3 denominator: 10]; § § // print it § printf( "The fraction is: " ); § [frac2 print]; § printf( "/n" ); § § // free memory § [frac release]; § [frac2 release]; § § return 0; } § The fraction is: 3/10 The fraction is: (3/10) § @protocol Printing § -(void) print; @end § #import <Foundation/NSObject.h> § #import "Printing.h" § § @interface Fraction: NSObject <Printing, NSCopying> { § int numerator; § int denominator; § } § § -(Fraction*) initWithNumerator: (int) n denominator: (int) d; § -(void) setNumerator: (int) d; § -(void) setDenominator: (int) d; § -(void) setNumerator: (int) n andDenominator: (int) d; § -(int) numerator; § -(int) denominator; @end § #import "Fraction.h" § #import <stdio.h> § § @implementation Fraction § -(Fraction*) initWithNumerator: (int) n denominator: (int) d { § self = [super init]; § § if ( self ) { § [self setNumerator: n andDenominator: d]; § } § § return self; § } § § -(void) print { § printf( "%i/%i", numerator, denominator ); § } § § -(void) setNumerator: (int) n { § numerator = n; § } § § -(void) setDenominator: (int) d { § denominator = d; § } § § -(void) setNumerator: (int) n andDenominator: (int) d { § numerator = n; § denominator = d; § } § § -(int) denominator { § return denominator; § } § § -(int) numerator { § return numerator; § } § § -(Fraction*) copyWithZone: (NSZone*) zone { § return [[Fraction allocWithZone: zone] initWithNumerator: numerator § denominator: denominator]; § } @end § #import <Foundation/NSObject.h> § #import "Printing.h" § § @interface Complex: NSObject <Printing> { § double real; § double imaginary; § } § § -(Complex*) initWithReal: (double) r andImaginary: (double) i; § -(void) setReal: (double) r; § -(void) setImaginary: (double) i; § -(void) setReal: (double) r andImaginary: (double) i; § -(double) real; § -(double) imaginary; @end § #import "Complex.h" § #import <stdio.h> § § @implementation Complex § -(Complex*) initWithReal: (double) r andImaginary: (double) i { § self = [super init]; § § if ( self ) { § [self setReal: r andImaginary: i]; § } § § return self; § } § § -(void) setReal: (double) r { § real = r; § } § § -(void) setImaginary: (double) i { § imaginary = i; § } § § -(void) setReal: (double) r andImaginary: (double) i { § real = r; § imaginary = i; § } § § -(double) real { § return real; § } § § -(double) imaginary { § return imaginary; § } § § -(void) print { § printf( "%_f + %_fi", real, imaginary ); § } @end § #import <stdio.h> § #import "Fraction.h" § #import "Complex.h" § § int main( int argc, const char *argv[] ) { § // create a new instance § Fraction *frac = [[Fraction alloc] initWithNumerator: 3 denominator: 10]; § Complex *comp = [[Complex alloc] initWithReal: 5 andImaginary: 15]; § id <Printing> printable; § id <NSCopying, Printing> copyPrintable; § § // print it § printable = frac; § printf( "The fraction is: " ); § [printable print]; § printf( "/n" ); § § // print complex § printable = comp; § printf( "The complex number is: " ); § [printable print]; § printf( "/n" ); § § // this compiles because Fraction comforms to both Printing and NSCopyable § copyPrintable = frac; § § // this doesn't compile because Complex only conforms to Printing § //copyPrintable = comp; § § // test conformance § § // true § if ( [frac conformsToProtocol: @protocol( NSCopying )] == YES ) { § printf( "Fraction conforms to NSCopying/n" ); § } § § // false § if ( [comp conformsToProtocol: @protocol( NSCopying )] == YES ) { § printf( "Complex conforms to NSCopying/n" ); § } § § // free memory § [frac release]; § [comp release]; § § return 0; } § The fraction is: 3/10 § The complex number is: 5.000000 + 15.000000i Fraction conforms to NSCopying § ... § -(void) dealloc { § printf( "Deallocing fraction/n" ); § [super dealloc]; § } ... § #import "Fraction.h" § #import <stdio.h> § § int main( int argc, const char *argv[] ) { § Fraction *frac1 = [[Fraction alloc] init]; § Fraction *frac2 = [[Fraction alloc] init]; § § // print current counts § printf( "Fraction 1 retain count: %i/n", [frac1 retainCount] ); § printf( "Fraction 2 retain count: %i/n", [frac2 retainCount] ); § § // increment them § [frac1 retain]; // 2 § [frac1 retain]; // 3 § [frac2 retain]; // 2 § § // print current counts § printf( "Fraction 1 retain count: %i/n", [frac1 retainCount] ); § printf( "Fraction 2 retain count: %i/n", [frac2 retainCount] ); § § // decrement § [frac1 release]; // 2 § [frac2 release]; // 1 § § // print current counts § printf( "Fraction 1 retain count: %i/n", [frac1 retainCount] ); § printf( "Fraction 2 retain count: %i/n", [frac2 retainCount] ); § § // release them until they dealloc themselves § [frac1 release]; // 1 § [frac1 release]; // 0 § [frac2 release]; // 0 } § Fraction 1 retain count: 1 § Fraction 2 retain count: 1 § Fraction 1 retain count: 3 § Fraction 2 retain count: 2 § Fraction 1 retain count: 2 § Fraction 2 retain count: 1 § Deallocing fraction Deallocing fraction § #import <Foundation/NSObject.h> § #import <Foundation/NSString.h> § § @interface AddressCard: NSObject { § NSString *first; § NSString *last; § NSString *email; § } § § -(AddressCard*) initWithFirst: (NSString*) f § last: (NSString*) l § email: (NSString*) e; § -(NSString*) first; § -(NSString*) last; § -(NSString*) email; § -(void) setFirst: (NSString*) f; § -(void) setLast: (NSString*) l; § -(void) setEmail: (NSString*) e; § -(void) setFirst: (NSString*) f § last: (NSString*) l § email: (NSString*) e; § -(void) setFirst: (NSString*) f last: (NSString*) l; § -(void) print; @end § #import "AddressCard.h" § #import <stdio.h> § § @implementation AddressCard § -(AddressCard*) initWithFirst: (NSString*) f § last: (NSString*) l § email: (NSString*) e { § self = [super init]; § § if ( self ) { § [self setFirst: f last: l email: e]; § } § § return self; § } § § -(NSString*) first { § return first; § } § § -(NSString*) last { § return last; § } § § -(NSString*) email { § return email; § } § § -(void) setFirst: (NSString*) f { § [f retain]; § [first release]; § first = f; § } § § -(void) setLast: (NSString*) l { § [l retain]; § [last release]; § last = l; § } § § -(void) setEmail: (NSString*) e { § [e retain]; § [email release]; § email = e; § } § § -(void) setFirst: (NSString*) f § last: (NSString*) l § email: (NSString*) e { § [self setFirst: f]; § [self setLast: l]; § [self setEmail: e]; § } § § -(void) setFirst: (NSString*) f last: (NSString*) l { § [self setFirst: f]; § [self setLast: l]; § } § § -(void) print { § printf( "%s %s <%s>", [first cString], § [last cString], § [email cString] ); § } § § -(void) dealloc { § [first release]; § [last release]; § [email release]; § § [super dealloc]; § } @end § #import "AddressCard.h" § #import <Foundation/NSString.h> § #import <stdio.h> § § int main( int argc, const char *argv[] ) { § NSString *first =[[NSString alloc] initWithCString: "Tom"]; § NSString *last = [[NSString alloc] initWithCString: "Jones"]; § NSString *email = [[NSString alloc] initWithCString: "tom@jones.com"]; § AddressCard *tom = [[AddressCard alloc] initWithFirst: first § last: last § email: email]; § § // we're done with the strings, so we must dealloc them § [first release]; § [last release]; § [email release]; § § // print to show the retain count § printf( "Retain count: %i/n", [[tom first] retainCount] ); § [tom print]; § printf( "/n" ); § § // free memory § [tom release]; § § return 0; } § Retain count: 1 Tom Jones <tom@jones.com> § #import <Foundation/NSString.h> § #import <Foundation/NSAutoreleasePool.h> § #import <stdio.h> § § int main( int argc, const char *argv[] ) { § NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; § NSString *str1 = @"constant string"; § NSString *str2 = [NSString stringWithString: @"string managed by the pool"]; § NSString *str3 = [[NSString alloc] initWithString: @"self managed string"]; § § // print the strings § printf( "%s retain count: %x/n", [str1 cString], [str1 retainCount] ); § printf( "%s retain count: %x/n", [str2 cString], [str2 retainCount] ); § printf( "%s retain count: %x/n", [str3 cString], [str3 retainCount] ); § § // free memory § [str3 release]; § § // free pool § [pool release]; § return 0; } § constant string retain count: ffffffff § string managed by the pool retain count: 1 self managed string retain count: 1 § ... § +(Fraction*) fractionWithNumerator: (int) n denominator: (int) d; § ... § ... § +(Fraction*) fractionWithNumerator: (int) n denominator: (int) d { § Fraction *ret = [[Fraction alloc] initWithNumerator: n denominator: d]; § [ret autorelease]; § § return ret; § } ... § #import <Foundation/NSAutoreleasePool.h> § #import "Fraction.h" § #import <stdio.h> § § int main( int argc, const char *argv[] ) { § NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; § Fraction *frac1 = [Fraction fractionWithNumerator: 2 denominator: 5]; § Fraction *frac2 = [Fraction fractionWithNumerator: 1 denominator: 3]; § § // print frac 1 § printf( "Fraction 1: " ); § [frac1 print]; § printf( "/n" ); § § // print frac 2 § printf( "Fraction 2: " ); § [frac2 print]; § printf( "/n" ); § § // this causes a segmentation fault § //[frac1 release]; § § // release the pool and all objects in it § [pool release]; § return 0; } § Fraction 1: 2/5 Fraction 2: 1/3 § #import <Foundation/NSArray.h> § #import <Foundation/NSString.h> § #import <Foundation/NSAutoreleasePool.h> § #import <Foundation/NSEnumerator.h> § #import <stdio.h> § § void print( NSArray *array ) { § NSEnumerator *enumerator = [array objectEnumerator]; § id obj; § § while ( obj = [enumerator nextObject] ) { § printf( "%s/n", [[obj description] cString] ); § } § } § § int main( int argc, const char *argv[] ) { § NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; § NSArray *arr = [[NSArray alloc] initWithObjects: § @"Me", @"Myself", @"I", nil]; § NSMutableArray *mutable = [[NSMutableArray alloc] init]; § § // enumerate over items § printf( "----static array/n" ); § print( arr ); § § // add stuff § [mutable addObject: @"One"]; § [mutable addObject: @"Two"]; § [mutable addObjectsFromArray: arr]; § [mutable addObject: @"Three"]; § § // print em § printf( "----mutable array/n" ); § print( mutable ); § § // sort then print § printf( "----sorted mutable array/n" ); § [mutable sortUsingSelector: @selector( caseInsensitiveCompare: )]; § print( mutable ); § § // free memory § [arr release]; § [mutable release]; § [pool release]; § § return 0; } § ----static array § Me § Myself § I § ----mutable array § One § Two § Me § Myself § I § Three § ----sorted mutable array § I § Me § Myself § One § Three Two § #import <Foundation/NSString.h> § #import <Foundation/NSAutoreleasePool.h> § #import <Foundation/NSDictionary.h> § #import <Foundation/NSEnumerator.h> § #import <Foundation/Foundation.h< § #import <stdio.h> § § void print( NSDictionary *map ) { § NSEnumerator *enumerator = [map keyEnumerator]; § id key; § § while ( key = [enumerator nextObject] ) { § printf( "%s => %s/n", § [[key description] cString], § [[[map objectForKey: key] description] cString] ); § } § } § § int main( int argc, const char *argv[] ) { § NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; § NSDictionary *dictionary = [[NSDictionary alloc] initWithObjectsAndKeys: § @"one", [NSNumber numberWithInt: 1], § @"two", [NSNumber numberWithInt: 2], § @"three", [NSNumber numberWithInt: 3], § nil]; § NSMutableDictionary *mutable = [[NSMutableDictionary alloc] init]; § § // print dictionary § printf( "----static dictionary/n" ); § print( dictionary ); § § // add objects § [mutable setObject: @"Tom" forKey: @"tom@jones.com"]; § [mutable setObject: @"Bob" forKey: @"bob@dole.com" ]; § § // print mutable dictionary § printf( "----mutable dictionary/n" ); § print( mutable ); § § // free memory § [dictionary release]; § [mutable release]; § [pool release]; § § return 0; } § ----static dictionary § 1 => one § 2 => two § 3 => three § ----mutable dictionary § bob@dole.com => Bob tom@jones.com => Tom Last modified: April 13, 2004. 
. 一书中撰写。如果你想得到更多详细信息及范例，请直接参考该书。这个网站上登载的所有范例皆经过他的允许，所以请勿复制转载。（译注：台湾出版书名为 C 程序语言第二版）这是 C 语言的设计者所写的书。
此对象是否是 classObj 的子孙或一员
此对象是否是 classObj 的一员
此对象是否有叫做 selector 的 method
此对象是否是由有能力响应指定 selector 的对象所产生
唤起此对象的指定 selector
中文翻译：William Shih (xamous)，January 7, 2005
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