diff options
Diffstat (limited to 'scala.html.markdown')
| -rw-r--r-- | scala.html.markdown | 32 |
1 files changed, 21 insertions, 11 deletions
diff --git a/scala.html.markdown b/scala.html.markdown index 7f545196..56f31f33 100644 --- a/scala.html.markdown +++ b/scala.html.markdown @@ -169,6 +169,12 @@ def sumOfSquaresShort(x: Int, y: Int): Int = x * x + y * y // Syntax for calling functions is familiar: sumOfSquares(3, 4) // => 25 +// You can use parameters names to specify them in different order +def subtract(x: Int, y: Int): Int = x - y + +subtract(10, 3) // => 7 +subtract(y=10, x=3) // => -7 + // In most cases (with recursive functions the most notable exception), function // return type can be omitted, and the same type inference we saw with variables // will work with function return values: @@ -278,21 +284,21 @@ val text = if (x == 10) "yeah" else "nope" ///////////////////////////////////////////////// val a = Array(1, 2, 3, 5, 8, 13) -a(0) -a(3) +a(0) // Int = 1 +a(3) // Int = 5 a(21) // Throws an exception val m = Map("fork" -> "tenedor", "spoon" -> "cuchara", "knife" -> "cuchillo") -m("fork") -m("spoon") +m("fork") // java.lang.String = tenedor +m("spoon") // java.lang.String = cuchara m("bottle") // Throws an exception val safeM = m.withDefaultValue("no lo se") -safeM("bottle") +safeM("bottle") // java.lang.String = no lo se val s = Set(1, 3, 7) -s(0) -s(1) +s(0) // Boolean = false +s(1) // Boolean = true /* Look up the documentation of map here - * http://www.scala-lang.org/api/current/index.html#scala.collection.immutable.Map @@ -313,15 +319,16 @@ s(1) // Why have this? val divideInts = (x: Int, y: Int) => (x / y, x % y) -divideInts(10, 3) // The function divideInts gives you the result and the remainder +// The function divideInts gives you the result and the remainder +divideInts(10, 3) // (Int, Int) = (3,1) // To access the elements of a tuple, use _._n where n is the 1-based index of // the element -val d = divideInts(10, 3) +val d = divideInts(10, 3) // (Int, Int) = (3,1) -d._1 +d._1 // Int = 3 -d._2 +d._2 // Int = 1 ///////////////////////////////////////////////// @@ -453,6 +460,9 @@ def matchEverything(obj: Any): String = obj match { // You can nest patterns: case List(List((1, 2, "YAY"))) => "Got a list of list of tuple" + + // Match any case (default) if all previous haven't matched + case _ => "Got unknown object" } // In fact, you can pattern match any object with an "unapply" method. This |