Basic JavaScript questions as diff. between let , var & const , hoisting , temporal deadzone , closure , event loop, call(), apply(), and bind() methods , diff b/w map() & filter() ,how to change constant array. React JS questions such as component, Real DOM & Virtual DOM , React optimization techniques , Hooks - useRef() ,useEffect() , form validation , how to call API from frontend, Redux CSS3 questions such as pseudo classes , visibility:hidden-vs-opacity:0 , :not Selector HTML questions such as what is