added an example of anonymous class and lambda expression (#13241)

Co-authored-by: Vartika_Nigam <[email protected]>

core-java-modules/core-java/src/main/java/com/baeldung/anonymousclass/AnonymousClassExample.java

@@ -0,0 +1,13 @@
+package com.baeldung.anonymousclass;
+
+public class AnonymousClassExample{
+
+    public static void main(String[] args){
+        Thread t1 = new Thread(new Runnable(){
+            @Override
+            public void run() {
+                System.out.println("Thread: "+Thread.currentThread().getName()+" started");
+            }
+        });
+    }
+}

core-java-modules/core-java/src/main/java/com/baeldung/lambdaexpression/LambdaExpressionExample.java

@@ -0,0 +1,9 @@
+package com.baeldung.lambdaexpression;
+
+public class LambdaExpressionExample{
+
+    public static void main(String[] args){
+        Thread t1 = new Thread(()->System.out.println("Thread: "+Thread.currentThread().getName()+" started"));
+        t1.start();
+    }
+}