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iOS

Posted by Jon Schenck
Jon Schenck
2,028 Points

What do the self. statements mean? In other words why are they used? I am just trying to understand them more.

???

1 Answer

Enrique Munguía
Enrique Munguía
14,311 Points
Enrique Munguía
Enrique Munguía
14,311 Points

The self keyword is used to reference members (i.e properties, methods, etc) of the current class, struct or enum. One common use case is within initializers, in this example we have an structure that represents a two dimensional point. The properties are called x and y, usually the arguments of the init method are called the same, in order to avoid ambiguity during the assignment, the properties are prepended with self.. If the arguments were called differently there would no need to use self. 

struct Point {
  let x: Int;
  let y: Int;

  init(x: Int, y: Int) {
    self.x = x;
    self.y = y;
  }
}

There are some cases where the use of self is obligatory for example when a closure is differently properties or methods of a class, if you don't include the sel.f you get a compiler error.