LukaJCB

//mutable
int x = 1;
var y = new Dictionary<string, string>();
//immutable
const int a = 1;
const var b = new Dictionary<string, string>(); // Won't compile

LukaJCB

let x = 123;
let mut y = "Hello";

LukaJCB

final Person frank = new Person("Frank", "Walker");
frank.setFirstName("Bob");
System.out.println(frank.getFirstName()) // prints "Bob"

LukaJCB

let num = if input > 0 then true else false

LukaJCB

def factorial(n: Int) : Int = {
  @tailrec
  def factorialWithAccumulator(acc: Int, n: Int) : Int = {
    if (number == 1) acc
    else factorialWithAccumulator(accumulator * n, n - 1)
  }
  factorialWithAccumulator(1, n)
}

LukaJCB

String constructionFirm = person.getResidence().getAddress().getConstructionFirm();
//Can't do this because residence, address or constructionFirm could be null.

String constructionFirm = null;
if(person != null){
   Residence residence = person.getResidence();
   if(residence != null){
      Address address = residence.getAddress();
      if(address != null){
         constructionFirm = adress.getConstructionFirm();

LukaJCB

def constructionFirm = person?.residence?.address?.constructionFirm

LukaJCB

constructionFirm = person&.residence&.address&.constructionFirm

LukaJCB

personOption |> Option.bind (fun p -> p.residence)
  |> Option.bind (fun r -> r.address)
  |> Option.map (fun a -> a.constructionFirm)

LukaJCB

Optional<String> firm = personOption
   .flatMap(Person::getResidence)
   .flatMap(Residence::getAddress)
   .map(Address::getConstructionFirm)