1.Hoisting 2.Closures 3.Void elements in html 4.Virtual DOM in react comparison with Real DOM 5.What is ref,forward ref 6.let,const,var? 7.Array methods in JavaScript 8.Hooks in react 9.HTML5 and HTML old versions difference 10.ES6 features 11.Semantic tags in html 13.Write react code to display elements from an array 14.What is props and state in react 15.Higher order components in react 16.Why react? 17.What is JSX? 18.Event loop ?