Swift class constants are mutable within the initialiser

gistfile1.swift

// A follow-up to the blog post here:
// http://www.scottlogic.com/blog/2014/11/20/swift-initialisation.html

class Foo { }

class Bar: Foo {
  
  // no initial value set here
  let myConstant: Int
  
  override init() {
    
    // the constant needs an initial value - but
    // you can set it more than once!
    myConstant = 77
    myConstant = 45
    
    super.init()
    
    // you can set it here also
    myConstant = 55 // 55
    println(myConstant)
  }
  
  func doSomething() {
    // but of course you cannot set it here!
    //myConstant = 66
  }
}

let bar = Bar()