Challenge 2.

momedalhouma · momedalhouma · commit 4cdaee2150d2 · 2019-09-26T15:41:03.000+02:00
jdk 12 used
diff --git a/pom.xml b/pom.xml
@@ -13,8 +13,8 @@
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
                 <configuration>
-                    <source>8</source>
-                    <target>8</target>
+                    <source>12</source>
+                    <target>12</target>
                 </configuration>
             </plugin>
         </plugins>
diff --git a/src/main/java/Challenge_2.java b/src/main/java/Challenge_2.java
@@ -0,0 +1,42 @@
+import java.util.function.Function;
+
+/**
+ * In this Challenge, We learn:
+ *    * String.join() method:   String message = String.join("-", "Java", "is", "cool");
+ *                                      message = "Java-is-cool";
+ *    * Function<String, String> function ----> function.apply() : given an argument of type String the function
+ *                                                                 return a String.
+ *    * the overridden method in a anonymous class could be called only if we reference the object:
+ *      new Jedi(){
+ *          overriddenMethod(){...}
+ *      };
+ *      the above method will be never used, unless we write
+ *      new Jedi(){
+ *            overriddenMethod(){...}
+ *      }.overriddenMethod();
+ *
+ */
+public class Challenge_2 {
+
+    interface Jedi{
+        String MASTER = "Yoda";
+
+        //default String attack(){return jump(jedi-> String.join(jedi, useSaber(), useForce())); }
+        default String attack(){
+            return jump(stringInput-> String.join(stringInput, useSaber(), this.useForce()));
+        }
+
+        private String jump( Function<String, String> function){
+            return function.apply("Luke");
+        }
+
+        private static String useSaber(){return "S";}
+
+        private String useForce(){return "F";}
+    }
+
+    public static void main( String[] args ) {
+        System.out.println(new Jedi(){
+            public String useForce(){return "X";}}.attack()+ Jedi.useSaber() + Jedi.MASTER);
+    }
+}
