// Scala is about expressions+
−
//+
−
//+
−
+
−
1 + 2+
−
+
−
val r1 = 1 + 2+
−
val r2 = r1 * r1+
−
+
−
val new_list = +
−
  for (n <- (1 to 10).toList) yield n * n+
−
+
−
+
−
def my_not_equal(x: Int, y: Int) : Boolean = {+
−
 !(x == y)+
−
}+
−
+
−
+
−
// why return is not needed in Scala+
−
+
−
def sum_even(ls: List[Int]): Int = {+
−
  val aux = for (x <- ls) yield {+
−
    if (x % 2 == 0) x else 0+
−
  }+
−
  aux.sum+
−
}+
−
+
−
sum_even(List(1,2,3,4,5,6))+
−
+
−
def sum_return(ls: List[Int]): Int = {+
−
  val aux = for (x <- ls) yield {+
−
    if (x % 2 == 0) (return x) else (return 0)+
−
  }+
−
  aux.sum[Int]+
−
}+
−
+
−
sum_return(List(2,3,4,5,6))+
−
+
−
+
−
// replace subexpressions should not +
−
// change the meaning, but with return it does:+
−
+
−
def sq1(n: Int): Int = n * n+
−
def sq2(n: Int): Int = return n * n+
−
+
−
def sum_squares(ls: List[Int]): Int = {  +
−
  (for (n <- ls) yield (return n * n)).sum[Int]+
−
}+
−
+
−
sum_squares(List(1,2,3,4,5,6))+
−