Why convenience keyword is even needed in Swift?

Question

Since Swift supports method and initializer overloading, you can put multiple init alongside each other and use whichever you deem convenient:

c         


        

Answer 1

Mostly clarity. From you second example,

init(name: String) {
    self.name = name
}

is required or designated. It has to initialize all your constants and variables. Convenience initializers are optional, and can typically be used to make initializing easier. For example, say your Person class has an optional variable gender:

var gender: Gender?

where Gender is an enum

enum Gender {
  case Male, Female
}

you could have convenience initializers like this

convenience init(maleWithName: String) {
   self.init(name: name)
   gender = .Male
}

convenience init(femaleWithName: String) {
   self.init(name: name)
   gender = .Female
}

Convenience initializers must call the designated or required initializers in them. If your class is a subclass, it must call super.init() within it's initialization.