Examples how to use closures

ClosureExamples.swift

/* regular closure */

/// definition of function with closure parameter
func test(closure: (Int) -> String) {
  let result = closure(42)
  print("Result is \(result)")
}

// using the function
test { i in
  return "\(i + 20)"
}
// above outputs "result is 62"



/// definition of function with closure parameter, the closure does not have arguments, only return value
func navigateTo<T: UIViewController>(controller: @escaping () -> T) {
  let target = controller()
  print("target is \(target)")
}

// using the function
navigateTo {
  let vc = UIViewController()
  return vc
}
// above outputs "target is <UIViewController: 0x...>"