1> How to optimize React component to render it less often? (using shouldComponentUpdate to determine if any relevant data changed)
2> What are best practices? (for example why not to use getInitialState, try to find others and know how to explain them)
3> React is rarely used by itself, so expect some questions about data layer, most commonly an implementation of flux:
4> What is flux? How it’s different from the more traditional MVC pattern?
5> How does Redux data flow work? (view, action creator, reducer, view — you should know and explain responsibilities of each; also how state is represented — state tree)
6> Comparison with Angular Js and VUE js?
7> Understanding on state, props, event handling, data sharing, ajax in react, polling, routing
8> Unit testing for React code
9> explain what is higher order component, control uncontrolled component in react.
10> Reducer return a new object or old one?
11> Explain diff between store and flux.
12> What is the difference between Virtual DOM and DOM?
13> Describe synthetic events in React. How it is different from Javascript Events.
14> Explain this.props.children
15> Differentiate controlled and uncontrolled components in React Js?
16> How to optimize React component to render it less often? (using shouldComponentUpdate to determine if any relevant data changed)