1. Recap of day 1

2. Variables
Scala: Java:
val s = “Hello World” public final String s = “Hello World”;
var i = 1 public int i = 1;

3. Methods
Scala: Java:
def add(x: Int, y: Int): Int = { public int add(int x, int y) {
x+y return x + y;
} }
def add(x: Int, y: Int) = x + y
def doSomething(text: String) { public void doSometing(String text) {
} }

4. Classes and constructors
Scala: Java:
class Person(val name: String) public class Person {
private final String name;
public Person(String name) {
this.name = name;
}
public String getName() {
return name;
}
}

5. Tuples
Scala: Java:
val tuple: Tuple2[Int, String] = Pair<Integer, String> tuple = new
Pair<Integer, String>(1, “apple”)
(1, “apple”)
val quadruple =
... yeah right... ;-)
(2, “orange”, 0.5d, false)

6. The Option type
val someOption: Option[String] = Some("value")
val noOption: Option[String] = None

7. First class funtions
val numbers = List(1, 2, 3, 4, 5)
numbers.filter(i => i > 2) // List(3, 4, 5)

8. Closures
val people = List(Person(“Alf”), Person(“Fredrik”))
val name = “Fredrik”
people.filter(_.name == name) // Person(“Fredrik”)

9. Pattern matching
val myObject = ...
val res = myObject match {
case i: Int if i == 1 => "Found an int which is 1"
case s: String => "Found a String"
case other => error("Unknown " + other)
}

10. Traits
trait Ordered[A] {
def compare(that: A): Int
def < (that: A): Boolean = (this compare that) < 0
def > (that: A): Boolean = (this compare that) > 0
def <= (that: A): Boolean = (this compare that) <= 0
def >= (that: A): Boolean = (this compare that) >= 0
}

11. Todays schedule
Higher order functions
Implicit conversions
XML support
Task: The Quiz game