 let struct2 = MyStruct(t: 12, u: "World")
 //struct2.u = "Planet" // Error: struct2 is immutable
 //struct2 = MyStruct(t: 10, u: "Defeat") // Error: struct2 is an immutable ref
+// Reason: Because in Swift, struct is value type.
+
 
 class MyClass {
   let t = 12

  AnyObject
******************/

let myString: AnyObject = "hello"
myString.cornerRadius // Returns nil

func someFunc(parameter: AnyObject!) {

  // Do something
}

// Top-tip: Casting array is still easy
func someArrayFunc(parameter: [AnyObject]!) {
  let newArray = parameter as [NSString]
  // Do something
