Programming in Scala 7/8/9/10

1.

scala> val someNumbers = List(-11,2,-12,8,9)

scala> someNumbers.filter( x=>x<8 )

scala> someNumbers.filter(_>0)

scala> val f= (_: Int)+(_: Int)

scala> someNumbers.foreach(println _)

 equals

 someNumbers.foreach(x => println(x))
2. closure

 def makeIncreaser(more: Int) = (x: Int) => x + more

3.

 scala> def twice(op: Double => Double, x: Double) = op(op(x))

 scala> twice(_ + 1, 5)

4.

In Scala it is forbidden to define a field and method with the same name in the same class, whereas this is

allowed in Java.

Generally, Scala has just two namespaces for definitions in place of Java's four. Java's four namespaces

are fields, methods, types, and packages. By contrast, Scala's two namespaces are:

• values (fields, methods, packages, and singleton objects)

• types (class and trait names)