diff --git a/Observable.js b/Observable.js
index 03545cd..d3e93ba 100644
--- a/Observable.js
+++ b/Observable.js
@@ -11,12 +11,23 @@ class ObserverList {
   }
   add(observer) {
     // todo add observer to list
+    return this.observerList.push(observer);
   }
   remove(observer) {
     // todo remove observer from list
+    const index=this.observerList.indexOf(observer);
+    if(index>-1){
+      return this.observerList.splice(index,1);
+    }
   }
   count() {
     // return observer list size
+    return this.observerList.length
+  }
+  get(index){
+    if(index>-1 && index<this.observerList.length){
+      return this.observerList[index]
+    }
   }
 }
 
@@ -26,12 +37,21 @@ class Subject {
   }
   addObserver(observer) {
     // todo add observer
+    this.observers.add(observer);
   }
   removeObserver(observer) {
     // todo remove observer
+    this.observers.remove(observer);
   }
   notify(...args) {
     // todo notify
+    const length=this.observers.count();
+    if(length>0){
+      for(let i=0;i<length;i++){
+        this.observers.get(i).update(...args)
+      }
+    }
+
   }
 }
 
diff --git a/PubSub.js b/PubSub.js
index 0c7999e..cd1be50 100644
--- a/PubSub.js
+++ b/PubSub.js
@@ -13,14 +13,25 @@ module.exports = class PubSub {
 
   subscribe(type, fn) {
     // todo subscribe
+    if(!this.subscribers[type]){
+      this.subscribers[type]=[];
+    }
+    this.subscribers[type].push(fn);
   }
 
   unsubscribe(type, fn) {
     // todo unsubscribe
+    delete this.subscribers[type]
   }
 
   publish(type, ...args) {
     // todo publish
+    if(!this.subscribers[type]){
+      return false
+    }
+    this.subscribers[type].forEach(fn=>{
+      fn(...args)
+    })
   }
 
 }