Eine kleine Einführung in Scala mit einem Hauptschwerpunkt auf den Vergleich mit Java. Innerhalb der Präsentation werden viele Codefragmente von Java mit analogen Fragmenten in Scala verglichen.

1. Sven Naumann, Marcel Rehfeld © Sven Naumann, Marcel Rehfeld

6. Scala im Vergleich zu Java vs. © Sven Naumann, Marcel Rehfeld

9. Einführung © Sven Naumann, Marcel Rehfeld

17. Objektorientierung © Sven Naumann, Marcel Rehfeld

28. Konstruktoren (3) public class TestClass{ public TestClass(int number) { if (number > 3) { System.out.println(”Enough testing."); } } public void doSomething() { ... } } TestClass test =new Testclass(4); // “Enough testing.” class TestClass(number:Int) { if (number > 3) { println(”Enough testing.") } def doSomething() = { ... } } var test = new TestClass(4) // “Enough testing.” © Sven Naumann, Marcel Rehfeld

32. Konstruktor Parameter (3) public class Complex { private int a, b; public Complex(int a, int b) { this.a = a; this.b = b; } public int getA() { return a; } public void setA(int a) { this.a = a; } public int getB() { return b; } public void setB(int b) { this.b = b; } } final Complex number = new Complex(1,0); number.setB(12); class Complex(var a:Int, var b:Int) val number = new Complex(1, 0) number.b = 12 © Sven Naumann, Marcel Rehfeld

33. Methoden © Sven Naumann, Marcel Rehfeld

43. Pattern Matching, Case Classes & Exceptions © Sven Naumann, Marcel Rehfeld

47. Case Classes © Sven Naumann, Marcel Rehfeld

50. Case Classes (3) © Sven Naumann, Marcel Rehfeld

51. Case Classes (4) class Color(val red:Int, val green:Int, val blue:Int) case class Red(r:Int) extends Color(r, 0, 0) case class Green(g:Int) extends Color(0, g, 0) case class Blue(b:Int) extends Color(0, 0, b) def printColor(c:Color) = c match { case Red(v) => println("Red: " + v) case Green(v) => println("Green: " + v) case Blue(v) => println("Blue: " + v) case col:Color => { print("R: " + col.red + ", ") print("G: " + col.green + ", ") println("B: " + col.blue) } case null => println("Invalid color") } © Sven Naumann, Marcel Rehfeld

53. Exception Handling © Sven Naumann, Marcel Rehfeld

56. Traits © Sven Naumann, Marcel Rehfeld

59. Traits (3) abstract class APerson { def sleep() } trait TStudent extends APerson { override def sleep() = { println("sleeping 8h") } def learn() = { println("learing..") } } trait TWorker extends APerson { override def sleep() = { println("sleeping 6h") } def work() = { println("working..") } } class CollegeStudent extends TWorker with TStudent { } © Sven Naumann, Marcel Rehfeld

62. Interoperabilität zwischen Java und Scala © Sven Naumann, Marcel Rehfeld

65. Vorteile und Nachteile © Sven Naumann, Marcel Rehfeld

69. Werkzeuge © Sven Naumann, Marcel Rehfeld

71. Einsatzgebiete und Ausblick © Sven Naumann, Marcel Rehfeld