3 files changed, 33 insertions, 0 deletions
diff --git a/Java-Kompendium/kap21/1/BerechnenInterface.java b/Java-Kompendium/kap21/1/BerechnenInterface.java
new file mode 100644
index 0000000..ec36dba
--- /dev/null
+++ b/Java-Kompendium/kap21/1/BerechnenInterface.java
@@ -0,0 +1,3 @@
+public interface BerechnenInterface {
+    int berechnen(int x, int y);
+}
diff --git a/Java-Kompendium/kap21/1/Main.java b/Java-Kompendium/kap21/1/Main.java
new file mode 100644
index 0000000..3c34118
--- /dev/null
+++ b/Java-Kompendium/kap21/1/Main.java
@@ -0,0 +1,10 @@
+public class Main {
+    private static void print(BerechnenInterface lambda) {
+        System.out.println(lambda.berechnen(2, 3));
+    }
+
+    public static void main(String[] arguments) {
+        print((a, b) -> a + b);
+        print((a, b) -> a * b);
+    }
+}
diff --git a/Java-Kompendium/kap21/Task2.java b/Java-Kompendium/kap21/Task2.java
new file mode 100644
index 0000000..8a10577
--- /dev/null
+++ b/Java-Kompendium/kap21/Task2.java
@@ -0,0 +1,20 @@
+import java.util.HashSet;
+import java.util.HashSet;
+
+public class Task2 {
+    public static void main(String[] arguments) {
+        var set = new HashSet<Integer>();
+
+        set.add(1);
+        set.add(3);
+        set.add(5);
+        set.add(7);
+        set.add(9);
+        set.add(11);
+        set.add(15);
+        set.add(20);
+        set.add(21);
+
+        set.forEach(v -> System.out.println(v * 2));
+    }
+}