Closures in Scala

Author: CodeLab20

Functions/Closures.scala

@@ -0,0 +1,34 @@
+/***
+ * Closures are functions that close around the environment.
+ * Closures are used to make up the functions from environment
+ * It is good practice to enclose around something stable. e.g. val
+ */
+
+class FunctionRunner(x:Int)
+{
+  def runFunction(y:Int => Int) = y(x)  
+}
+
+object Closures extends App{
+  val m = 200    //m is an outside variable. If m is of type var, function will change its value
+  val f = (x:Int) => x + m  //define function here
+  
+  val frnr = new FunctionRunner(100)
+  println("frnr.runFunction(f): " + frnr.runFunction(f))
+  
+  // using closure with a variable
+  var n = 200
+  val f2 = (x:Int) => x + n
+  println("frnr.runFunction(f2): " + frnr.runFunction(f2))
+  n = 300
+  println("After n = 300\nfrnr.runFunction(f2): " + frnr.runFunction(f2))
+}
+
+/**
+	Sample Output
+frnr.runFunction(f): 300
+frnr.runFunction(f2): 300
+After n = 300
+frnr.runFunction(f2): 400
+
+ */