How to write init method in Swift?

Question

I want to write an init method in Swift. Here I initialize an NSObject class in Objective-C:

-(id)initWithNewsDictionary:(NSDictionary *)dictionary {     self = [super init];     if (self) {         self.title           = dictionary[@"title"];         self.shortDescription = dictionary[@"description"];         self.newsDescription = dictionary[@"content:encoded"];         self.link            = dictionary[@"link"];         self.pubDate         = [self getDate:dictionary[@"pubDate"]];      }     return self; } 

How can I write this method in Swift ?

Answer 1

that could be good bases for your class, I guess:

class MyClass {      // you may need to set the proper types in accordance with your dictionarty's content     var title: String?     var shortDescription: String?     var newsDescription: String?     var link: NSURL?     var pubDate: NSDate?      //      init () {         // uncomment this line if your class has been inherited from any other class         //super.init()     }      //      convenience init(_ dictionary: Dictionary<String, AnyObject>) {         self.init()          title = dictionary["title"] as? NSString         shortDescription = dictionary["shortDescription"] as? NSString         newsDescription = dictionary["newsDescription"] as? NSString         link = dictionary["link"] as? NSURL         pubDate = self.getDate(dictionary["pubDate"])      }      //      func getDate(object: AnyObject?) -> NSDate? {         // parse the object as a date here and replace the next line for your wish...         return object as? NSDate     }  } 

advanced-mode

I would like to avoid to copy-pand-paste the keys in a project, so I'd put the possible keys into e.g. an enum like this:

enum MyKeys : Int {     case KeyTitle, KeyShortDescription, KeyNewsDescription, KeyLink, KeyPubDate     func toKey() -> String! {         switch self {         case .KeyLink:             return "title"         case .KeyNewsDescription:             return "newsDescription"         case .KeyPubDate:             return "pubDate"         case .KeyShortDescription:             return "shortDescription"         case .KeyTitle:             return "title"         default:             return ""         }     } } 

and you can improve your convenience init(...) method like e.g. this, and in the future you can avoid any possible mistyping of the keys in your code:

convenience init(_ dictionary: Dictionary<String, AnyObject>) {     self.init()      title = dictionary[MyKeys.KeyTitle.toKey()] as? NSString     shortDescription = dictionary[MyKeys.KeyShortDescription.toKey()] as? NSString     newsDescription = dictionary[MyKeys.KeyNewsDescription.toKey()] as? NSString     link = dictionary[MyKeys.KeyLink.toKey()] as? NSURL     pubDate = self.getDate(dictionary[MyKeys.KeyPubDate.toKey()])  } 

NOTE: that is just a raw idea of how you could do it, it is not necessary to use conveniece initializer at all, but it looked obvious choice regarding I don't know anything about your final class – you have shared one method only.

Answer 2

class myClass {     var text: String     var response: String?      init(text: String) {         self.text = text     } } 

See Swift: Initialization