ES6 classes example with WikedMap with closure

Author: loiane

chapter03/01-Stack3.js

@@ -0,0 +1,54 @@
+let Stack3 = (function () {
+
+    const items = new WeakMap();
+
+    class Stack3 {
+
+        constructor () {
+            items.set(this, []);
+        }
+
+        push(element){
+            let s = items.get(this);
+            s.push(element);
+            items.set(this, s);
+        };
+
+        pop(){
+            let s = items.get(this);
+            let r = s.pop();
+            items.set(this, s);
+            return r;
+        };
+
+        peek(){
+            let s = items.get(this);
+            return s[s.length-1];
+        };
+
+        isEmpty(){
+            return items.get(this).length == 0;
+        };
+
+        size(){
+            let s = items.get(this);
+            return s.length;
+        };
+
+        clear(){
+            items.set(this, []);
+        };
+
+        print(){
+            let s = items.get(this);
+            console.log(this.toString());
+        };
+
+        toString(){
+            return items.get(this).toString();
+        };
+    }
+
+    return Stack3;
+})();
+