Initial data commit

Task/Nested-function/Java/nested-function.java

@@ -0,0 +1,17 @@
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Function;
+
+public class NestedFunctionsDemo {
+
+    static String makeList(String separator) {
+        AtomicInteger counter = new AtomicInteger(1);
+
+        Function<String, String> makeItem = item -> counter.getAndIncrement() + separator + item + "\n";
+
+        return makeItem.apply("first") + makeItem.apply("second") + makeItem.apply("third");
+    }
+
+    public static void main(String[] args) {
+        System.out.println(makeList(". "));
+    }
+}