Added examples for java basics module

Java/java-basics-ii/JavaThisKeyword.java

@@ -0,0 +1,52 @@
+import java.util.*;
+
+public class JavaThisKeyword {
+    public static void main(String[] args) {
+        javaInstanceOfOperator();
+    }
+
+    public class User {
+        private String username;
+
+        public User(String username) {
+            setUsername(username);
+        }
+
+        public void setUsername(String username) {
+            this.username = username;
+        }
+    }
+
+    public class Person {
+        private String name;
+
+        public void setName(String name) {
+            this.name = name;
+        }
+
+        public void printName(String localName) {
+            System.out.println("Local variable name: " + localName);
+            System.out.println("Instance variable name: " + this.name);
+        }
+    }
+
+    public class UserProfile {
+        private String username;
+        private int userAge;
+
+        public UserProfile() {
+            this("John Doe", 30);
+        }
+
+        public UserProfile(String name) {
+            this(name, 30);
+        }
+
+        public UserProfile(String name, int age) {
+            this.username = name;
+            this.userAge = age;
+        }
+    }
+
+
+}