diff options
| -rw-r--r-- | objective-c.html.markdown | 42 |
1 files changed, 22 insertions, 20 deletions
diff --git a/objective-c.html.markdown b/objective-c.html.markdown index 38b2cc52..f2787649 100644 --- a/objective-c.html.markdown +++ b/objective-c.html.markdown @@ -297,9 +297,9 @@ int main (int argc, const char * argv[]) } // Convenient notation for public access variables to auto generate a setter method. // By default, setter method name is 'set' followed by @property variable name. -@property int propInt; // Setter method name = 'setCount' +@property int propInt; // Setter method name = 'setPropInt' @property (copy) id copyId; // (copy) => Copy the object during assignment. -// (readonly) => Cannot set value outside interface. +// (readonly) => Cannot set value outside @interface. @property (readonly) NSString *roString; // Use @synthesize in @implementation to create accessor. // You can customize the getter and setter names instead of using default 'set' name: @property (getter=lengthGet, setter=lengthSet:) int length; @@ -307,16 +307,17 @@ int main (int argc, const char * argv[]) // Methods +/- (return type)methodSignature:(Parameter Type *)parameterName; -// + for class method. +// + for class methods: + (NSString *)classMethod; + (MyClass *)myClassFromHeight:(NSNumber *)defaultHeight; -// - for instance methods. +// - for instance methods: - (NSString *)instanceMethodWithParameter:(NSString *)string; - (NSNumber *)methodAParameterAsString:(NSString*)string andAParameterAsNumber:(NSNumber *)number; // Constructor methods with arguments: - (id)initWithDistance:(int)defaultDistance; +// Objective-C method names are very descriptive. Always name methods according to their arguments. @end // States the end of the interface. @@ -333,29 +334,30 @@ NSLog(@"%i", [myClass lengthGet]); // prints => 32 myClass.count = 45; NSLog(@"%i", myClass.count); // prints => 45 +// Call class methods: +NSString *classMethodString = [MyClass classMethod]; +MyClass *classFromName = [MyClass myClassFromName:@"Hello"]; + +// Call instance methods: +MyClass *myClass = [[MyClass alloc] init]; // Create MyClass object instance. +NSString *stringFromInstanceMethod = [myClass instanceMethodWithParameter:@"Hello"]; + // Selectors. -// Way of dynamically represent methods. Used to call methods of a class, pass methods -// through functions to tell other classes they should call it, and save to methods +// Way to dynamically represent methods. Used to call methods of a class, pass methods +// through functions to tell other classes they should call it, and to save methods // as a variable. -// SEL is data type. @selector() returns a selector from method name provided. +// SEL is the data type. @selector() returns a selector from method name provided. // methodAParameterAsString:andAParameterAsNumber: is method name for method in MyClass SEL selectorVar = @selector(methodAParameterAsString:andAParameterAsNumber:); if ([myClass respondsToSelector:selectorVar]) { // Checks if class contains method. - // Must put method arguments into one object to send to performSelector. + // Must put all method arguments into one object to send to performSelector function. NSArray *arguments = [NSArray arrayWithObjects:@"Hello", @4, nil]; - [myClass performSelector:selectorVar withObject:arguments]; // Calls the method + [myClass performSelector:selectorVar withObject:arguments]; // Calls the method. } else { + // NSStringFromSelector() returns a NSString of the method name of a given selector. NSLog(@"MyClass does not have method: %@", NSStringFromSelector(selectedVar)); } -// Call class methods: -NSString *classMethodString = [MyClass classMethod]; -MyClass *classFromName = [MyClass myClassFromName:@"Hello"]; - -// Call instance methods: -MyClass *myClass = [[MyClass alloc] init]; // Create MyClass object instance. -NSString *stringFromInstanceMethod = [myClass instanceMethodWithParameter:@"Hello"]; - // Implement the methods in an implementation (MyClass.m) file: @implementation MyClass { long distance; // Private access instance variable. @@ -384,13 +386,13 @@ distance = 18; // References "long distance" from MyClass implementation. [super dealloc]; // and call parent class dealloc. } -// Constructors are a way of creating instances of classes. +// Constructors are a way of creating instances of a class. // This is a default constructor which is called when the object is initialized. - (id)init { if ((self = [super init])) // 'super' used to access methods from parent class. { - self.count = 1; // 'self' used for object to send messages to itself. + self.count = 1; // 'self' used for object to call itself. } return self; } @@ -422,7 +424,7 @@ distance = 18; // References "long distance" from MyClass implementation. return @42; } -// If you create a method in @implementation but do not include in @interface, it is private. +// To create a private method, create the method in the @implementation but not in the @interface. - (NSNumber *)secretPrivateMethod { return @72; } |