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Diffstat (limited to 'objective-c.html.markdown')
| -rw-r--r-- | objective-c.html.markdown | 63 |
1 files changed, 59 insertions, 4 deletions
diff --git a/objective-c.html.markdown b/objective-c.html.markdown index 89901308..097cb846 100644 --- a/objective-c.html.markdown +++ b/objective-c.html.markdown @@ -1,25 +1,28 @@ --- - language: Objective-C contributors: - ["Eugene Yagrushkin", "www.about.me/yagrushkin"] - ["Yannick Loriot", "https://github.com/YannickL"] - ["Levi Bostian", "https://github.com/levibostian"] - ["Clayton Walker", "https://github.com/cwalk"] + - ["Fernando Valverde", "http://visualcosita.xyz"] filename: LearnObjectiveC.m - --- Objective-C is the main programming language used by Apple for the OS X and iOS operating systems and their respective frameworks, Cocoa and Cocoa Touch. It is a general-purpose, object-oriented programming language that adds Smalltalk-style messaging to the C programming language. -```objective_c +```objective-c // Single-line comments start with // /* Multi-line comments look like this */ +// XCode supports pragma mark directive that improve jump bar readability +#pragma mark Navigation Functions // New tag on jump bar named 'Navigation Functions' +#pragma mark - Navigation Functions // Same tag, now with a separator + // Imports the Foundation headers with #import // Use <> to import global files (in general frameworks) // Use "" to import local files (from project) @@ -149,6 +152,12 @@ int main (int argc, const char * argv[]) [mutableDictionary setObject:@"value2" forKey:@"key2"]; [mutableDictionary removeObjectForKey:@"key1"]; + // Change types from Mutable To Immutable + //In general [object mutableCopy] will make the object mutable whereas [object copy] will make the object immutable + NSMutableDictionary *aMutableDictionary = [aDictionary mutableCopy]; + NSDictionary *mutableDictionaryChanged = [mutableDictionary copy]; + + // Set object NSSet *set = [NSSet setWithObjects:@"Hello", @"Hello", @"World", nil]; NSLog(@"%@", set); // prints => {(Hello, World)} (may be in different order) @@ -593,6 +602,52 @@ int main (int argc, const char * argv[]) { @end +// Starting in Xcode 7.0, you can create Generic classes, +// allowing you to provide greater type safety and clarity +// without writing excessive boilerplate. +@interface Result<__covariant A> : NSObject + +- (void)handleSuccess:(void(^)(A))success + failure:(void(^)(NSError *))failure; + +@property (nonatomic) A object; + +@end + +// we can now declare instances of this class like +Result<NSNumber *> *result; +Result<NSArray *> *result; + +// Each of these cases would be equivalent to rewriting Result's interface +// and substituting the appropriate type for A +@interface Result : NSObject +- (void)handleSuccess:(void(^)(NSArray *))success + failure:(void(^)(NSError *))failure; +@property (nonatomic) NSArray * object; +@end + +@interface Result : NSObject +- (void)handleSuccess:(void(^)(NSNumber *))success + failure:(void(^)(NSError *))failure; +@property (nonatomic) NSNumber * object; +@end + +// It should be obvious, however, that writing one +// Class to solve a problem is always preferable to writing two + +// Note that Clang will not accept generic types in @implementations, +// so your @implemnation of Result would have to look like this: + +@implementation Result + +- (void)handleSuccess:(void (^)(id))success + failure:(void (^)(NSError *))failure { + // Do something +} + +@end + + /////////////////////////////////////// // Protocols /////////////////////////////////////// @@ -682,7 +737,7 @@ addUp = ^(int n) { // Remove (int n) to have a block that doesn't take in any pa mutableVar = 32; // Assigning new value to __block variable. return n + outsideVar; // Return statements are optional. } -int addUp = add(10 + 16); // Calls block code with arguments. +int addUp = addUp(10 + 16); // Calls block code with arguments. // Blocks are often used as arguments to functions to be called later, or for callbacks. @implementation BlockExample : NSObject |