[Add] Stack

data_structure/stack.js

@@ -0,0 +1,30 @@
+function Stack () {
+  this.data = [];
+}
+
+Stack.prototype.push = function (newData) {
+  this.data.push(newData);
+}
+
+Stack.prototype.pop = function () {
+  return this.data.pop() || null;
+}
+
+Stack.prototype.getSize = function () {
+  return this.data.length;
+}
+
+const stack = new Stack();
+
+
+stack.push(3);
+stack.push(2);
+stack.push(4);
+stack.push(6);
+console.log(stack.data);
+console.log(stack.getSize());
+stack.pop();
+stack.pop();
+console.log(stack.data);
+stack.pop();
+console.log(stack.getSize());