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--- programmiersprachen:scala [2015/10/10 17:23] – phreazer
+++ programmiersprachen:scala [2017/02/19 15:36] – phreazer
@@ Line 1: / Line 1: @@
-Scala
+====== Scala ======
-**Sca**lable **la**nga
-====== Start ======
+**Sca**lable **la**nguage
+===== Start =====
   * No primitive types, everything is an object
@@ Line 12: / Line 14: @@
-===== Hello World =====
+==== Hello World ====
 <code scala>
 object HelloWorld {
@@ Line 28: / Line 30: @@
 <code scala>
 for (i <- 1 to 10) println(i)
+</code>
+<code scala>
+// different steps
+for (i <- 4 to (17,3)) println(i)
+// other data types than int
+for (s <- myList) println(s)
+// multiple generators
+for (i <- 0 to 2; j <- 3 to 4) println(i+" "+j)
+// filter
+    for {i <- 1 to 6
+         j <- 1 to 6
+         if (i % 2 == 0)
+         if (j % 2 != 0)} println(i+" "+j)
+// yield
+    val list: List[Int] = List(1,2,3,4)
+    val result = for (i <- list) yield i * 2
+    println(result)
 </code>
 ==== match ====
@@ Line 40: / Line 64: @@
 </code>
-==== Singleton objects ====
+===== Singleton objects =====
 There are no static methods/vars in scala and singleton objects can't be constructed using a constructor with new.
@@ Line 54: / Line 78: @@
 </code>
-==== Companion object ====
+===== Companion object =====
 Prerequisite: object and class have the same name and are defined in the same file. Companion objects can access their private variables. Singleton objects without companion clases are standalone objects.
-==== Case classes ====
+===== Case classes =====
   * Use a factory method for construction
@@ Line 71: / Line 95: @@
 </code>
-==== Inheritance ====
+===== Inheritance =====
+Scala doesn't support multiple inheritance.
 class B(arg:Int) extends A {}
@@ Line 77: / Line 103: @@
 Functions can be overridden with overide before func definition.
+Overridding classes, functions or variables can be forbidden with prefix final.
+==== Abstract classes ====
+Difference to Traits: Abstract classes can have constructors. A class which inherits from an abstract class can't inherit from another.
+The usage of override is optional.
+==== Packages object ====
+Objects which are visible in a whole package.
+===== Identity and equality =====
+==-Operator checks equality (identity in Java)
+eq-Operator checks identity
+eq and ne are only defined for clases of type scala.AnyRef.