diff --git a/ex-1.js b/ex-1.js
index c1b94a3..bb5a517 100644
--- a/ex-1.js
+++ b/ex-1.js
@@ -1,3 +1,29 @@
-class EmailNotification { }
+class EmailNotification { 
+    constructor(notificationId, createdTime, content, receiver) {
+        this.notificationId = notificationId;
+        this.createdTime = createdTime;
+        this.content = content;
+        this.receiver = receiver;
+    }
+    send() {
+        console.log(`Notification has been sent to ${this.receiver}`);
+    }
+}
 
-class SMSNotification { }
+class SMSNotification { 
+    constructor(notificationId, createdTime, content, phoneNumber) {
+        this.notificationId = notificationId;
+        this.createdTime = createdTime;
+        this.content = content;
+        this.phoneNumber = phoneNumber;
+    }
+    send() {
+        console.log(`Notification has been sent to ${this.phoneNumber}`);
+    }
+}
+
+const emailNotification = new EmailNotification(1, "2024-06-25 09:00", "Hello, this is an email notification", "example@example.com");
+const smsNotification = new SMSNotification(2, "2024-06-25 10:00", "Hello, this is an SMS notification", "1234567890");
+
+emailNotification.send(); 
+smsNotification.send(); 
diff --git a/ex-2.js b/ex-2.js
index 2f39244..3cee05b 100644
--- a/ex-2.js
+++ b/ex-2.js
@@ -1,5 +1,31 @@
-class Notification { }
+class Notification {
+    constructor(notificationId, createdTime, content, receiver) {
+        this.notificationId = notificationId;
+        this.createdTime = createdTime;
+        this.content = content;
+        this.receiver = receiver;
+    }
+    send() {
+        console.log(`Notification has been sent to ${this.receiver}`);
+    } 
 
-class EmailNotification { }
+}
 
-class SMSNotification { }
+class EmailNotification extends Notification {
+    constructor(notificationId, createdTime, content, receiver) {
+        super(notificationId, createdTime, content, receiver);
+    }
+ }
+
+class SMSNotification extends Notification { 
+    constructor(notificationId, createdTime, content, receiver) {
+        super(notificationId, createdTime, content, receiver);
+    }
+}
+
+const emailNotification = new EmailNotification(1, "2024-06-25 09:00", "Hello, this is an email notification", "example@example.com");
+const smsNotification = new SMSNotification(2, "2024-06-25 10:00", "Hello, this is an SMS notification", "1234567890");
+
+
+emailNotification.send(); 
+smsNotification.send(); 
\ No newline at end of file
diff --git a/ex-3.js b/ex-3.js
index 36756a7..30ce652 100644
--- a/ex-3.js
+++ b/ex-3.js
@@ -1 +1,83 @@
 //  Start coding here
+class User {
+    constructor (id, name, email) {
+        this.id = id;
+        this.name = name;
+        this.email = email;
+    }
+}
+
+class PostList {
+    constructor (posts) {
+        this.posts = posts || [];
+    } 
+    addPost(post) {
+        this.posts.push({
+          id: this.posts.length + 1,
+          title: post.title,
+          content: post.content,
+          comments: post.comments,
+        });
+    }
+    sharePost(postTitle) {
+        console.log(`You've shared post ${postTitle} to your friend.`)
+    }
+}
+
+class Post {
+    constructor (id, title, content, comment) {
+        this.id = id;
+        this.title = title;
+        this.content = content;
+        this.comment = [];
+    }
+    addComment(comment) {
+        this.comment.push(comment);
+    }
+}
+
+class Comment {
+    constructor (id, content, createdBy, like) {
+        this.id = id;
+        this.content = content;
+        this.createdBy = createdBy;
+        this.like = 0;
+    }
+    addLike() {
+        this.like++;
+    }
+}
+
+class Facebook {
+    constructor (groupList, pageList) {
+        this.groupList = [];
+        this.pageList = [];
+    }
+    addGroup(group) {
+        this.groupList.push(group);
+    }
+    addPage(page) {
+        this.pageList.push(page);
+    }
+}
+
+class FacebookPage {
+    constructor (name) {
+        this.name = name;
+    }
+}
+
+class FacebookGroup {
+    constructor (name) {
+        this.name = name;
+    }
+}
+
+class notification {
+    constructor (id) {
+        this.id = id;
+    }
+    send(comment, post) {
+        console.log(`Notification: ${comment.createdBy.name} has just commented on this post—"${post.title}"`);
+    }
+}