General
  1. How is Stateless component different from a Stateful component?
  2. What is the difference between state and props?
  3. What can you do if the expression contains more than one line?
  4. What kind of information controls a segment in React?
  5. Explain DOM Diffing in React.
  6. What do you understand by the term polling?
  7. What’s the difference between an Element and a Component in React?
  8. Why should we not call setState in componentWillUnmount?
  9. What is the difference between React Native and React?
  10. What are React Hooks?
  11. When would you use a Class Component over a Functional Component?
  12. How to prevent a function from being called multiple times?
  13. Describe how events are handled in React.
  14. How to dispatch the data in-store?
  15. What do you understand by “Single source of truth”?
  16. Why is switch keyword used in React Router v4?
  17. How do you tell React to build in Production mode and what will that do?
  18. How do you access imperative API of web components?
  19. What is the benefit of strict mode?
  20. What is the difference between createElement and cloneElement?
  21. What are the features of ReactJS?
  22. What are the rules one needs to follow regarding hooks?
  23. What are the conditions to safely use the index as a key?
  24. Explain Presentational segment
  25. What is Relay?
  26. Can we make changes inside child components?
  27. What is route based code splitting?
  28. Explain the purpose of render() in React.
  29. What is render hijacking?
  30. What are React Events?
  31. What do you know about Flux?
  32. What is ReactDOMServer?
  33. How do the parent and child components exchange information?
  34. Where would you put AJAX calls in your React code?
  35. What is the use of Webpack?
  36. What is the difference between DOM and virtual DOM in React.js?
  37. Why do we need a Router to React?
  38. Why did you choose to work with react?
  39. List down the advantages of React Router.
  40. What is create-react-app?
  41. What are some of the major advantages to using react when building UIs?
  42. Why are you not required to use inheritance?
  43. How is React different from Angular and VUE?
  44. What is the second argument that can optionally be passed to setState and what is its purpose?
  45. What are Higher Order Components(HOC)?
  46. What is suspense component?
  47. Is it possible to display props on a parent component?
  48. Name 3 ways to create a component in React and its differences.
  49. Is setState() async? Why?
  50. What is the point of renderToNodeStream method?
  51. What is prop drilling and how can you avoid it?
  52. What do you understand by “In React, everything is a component.”
  53. How do you say that state updates are merged?
  54. What is the behavior of uncaught errors in react 16?
  55. How does JSX prevent Injection Attacks?
  56. What do you understand by mixin or higher order components in ReactJS?
  57. What do you understand by Props in React?
  58. How is Virtual-DOM more efficient than Dirty checking?
  59. Is it mandatory to define constructor for React component?
  60. What is the difference between a controlled component and an uncontrolled component?
  61. What are the rules needs to follow for hooks?
  62. React has something called a state. What is it and how it is used?
  63. What is JSX?
  64. Explain the use of Redux thunk?
  65. Is setState() is async? Why is setState() in React Async instead of Sync?
  66. What is the difference between async mode and concurrent mode?
  67. What does shouldComponentUpdate do and why is it important?
  68. Explain React Decorators
  69. What are the different phases of React component’s lifecycle?
  70. What is the purpose of eslint plugin for hooks?
  71. How would you debug an issue in react code? What debugging tools have you used?
  72. What are the lifecycle methods of ReactJS?
  73. How is ReactJs different from AngularJS?
  74. What would be two of the most significant drawbacks of React?
  75. What are synthetic events in React?
  76. Can you force a React component to rerender without calling setState?
  77. What is arrow function in React? How is it used?
  78. Mention the key benefits of Flux?
  79. Why are fragments better than container divs?
  80. What are refs in React?
  81. Is it ref argument available for all functions or class components?
  82. In ReactJS, why there is a need to capitalize on the components?
  83. What are the benefits of using typescript with reactjs?
  84. How would you structure a React application?
  85. What is the use of a super keyword in React?
  86. Why are String Refs considered legacy?
  87. When should you use the top-class elements for the function element?
  88. What is the methods order when component is re-rendered?
  89. Explain the Virtual DOM and its working.
  90. Is it possible to nest JSX elements into other JSX elements?