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How does React work?
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Xamarin React interview questions.
Only challenges
- 2.
What is context?
Answer:
- 3.
What is virtual DOM?
Answer:
- 4.
What is props in ReactJS?
Answer:
- 5.
What is the use of refs?
Answer:
- 6.
What is JEST?
Answer:
- 7.
What are the advantages of ReactJS?
Answer:
- 8.
What is ReactJS?
Answer:
- 9.
How to write comments in ReactJS?
Answer:
- 10.
How would you write an inline style in React?
Answer:
- 11.
What are the major features of ReactJS?
Answer:
- 12.
What are props in React?
Answer:
- 13.
What are the differences between a class component and functional component?
Answer:
- 14.
Where in a React component should you make an AJAX request?
Answer:
- 15.
What is the difference between state and props?
Answer:
- 16.
What is the difference between a Presentational component and a Container component?
Answer:
- 17.
What are refs used for in React?
Answer:
- 18.
What's the difference between a controlled component and an uncontrolled one in React?
Answer:
- 19.
What are controlled components?
Answer:
- 20.
What is state in ReactJS?
Answer:
- 21.
When to use a Class Component over a Functional Component?
Answer:
- 22.
What does it mean for a component to be mounted in React?
Answer:
- 23.
How do we pass a property from a parent component props to a child component?
Answer:
- 24.
What are fragments?
Answer:
- 25.
When rendering a list what is a key and what is it's purpose?
Answer:
- 26.
How to create refs?
Answer:
- 27.
What happens when you call setState?
Answer:
- 28.
What are stateful components?
Answer:
- 29.
How would you prevent a component from rendering in React?
Answer:
- 30.
What is JSX?
Answer:
- 31.
How error boundaries handled in React (15)?
Answer:
- 32.
Where is the state kept in a React + Redux application?
Answer:
- 33.
What are the limitations of ReactJS?
Answer:
- 34.
What is the difference between React Native and React?
Answer:
- 35.
What are stateless components?
Answer:
- 36.
How is React different from AngularJS (1.x)?
Answer:
- 37.
What is the point of Redux?
Answer:
- 38.
Why is it necessary to capitalize the components?
Answer:
- 39.
What is the difference between state and props?
Answer:
- 40.
What is Flow?
Answer:
- 41.
How to create components in ReactJS?
Answer:
- 42.
What is the purpose of callback function as an argument of setState?
Answer:
- 43.
What are portals in ReactJS?
Answer:
- 44.
How to pass a parameter to an event handler or callback?
Answer:
- 45.
What’s the difference between an "Element" and a "Component" in React?
Answer:
- 46.
What happens during the lifecycle of a React component?
Answer:
- 47.
What is Flux?
Answer:
- 48.
What is the difference between component and container in react Redux?
Answer:
- 49.
What is inline conditional expressions?
Answer:
- 50.
How do you prevent the default behavior in an event callback in React?
Answer:
- 51.
What is reconciliation?
Answer:
- 52.
What is the purpose of using super constructor with props argument?
Answer:
- 53.
What happens when you call "setState"?
Answer:
- 54.
Describe how events are handled in React.
Answer:
- 55.
What is the difference between Element and Component?
Answer:
- 56.
What are Higher-Order components?
Answer:
- 57.
Name the different lifecycle methods.
Answer:
- 58.
What is a higher order component?
Answer:
- 59.
What is JSX?
Answer:
- 60.
What is state in react?
Answer:
- 61.
What are controlled components?
Answer:
- 62.
What is a store in redux?
Answer:
- 63.
How would you prevent a component from rendering?
Answer:
- 64.
What don't you like about React?
Answer:
- 65.
What advantages are using arrow functions?
Answer:
- 66.
Why is it advised to pass a callback function to setState as opposed to an object?
Answer:
- 67.
What's the typical pattern for rendering a list of components from an array of data?
Answer:
- 68.
What are PropTypes in React?
Answer:
- 69.
What are Pure Components?
Answer:
- 70.
What are the advantages of React over VueJS?
Answer:
- 71.
Name some popular Flux Libraries
Answer:
- 72.
What's the typical flow of data like in a React + Redux app?
Answer:
- 73.
What are synthetic events in ReactJS?
Answer:
- 74.
What's an alternative way to avoid having to bind to this in event callback methods?
Answer:
- 75.
What are some limitations of things you shouldn't do in the component's render method?
Answer:
- 76.
How to bind methods or event handlers in JSX callbacks?
Answer:
- 77.
What is useState() in React?
Answer:
- 78.
What is the difference between createElement and cloneElement?
Answer:
- 79.
Why fragments are better than container divs?
Answer:
- 80.
What is prop drilling and how can you avoid it?
Answer:
- 81.
What is an action?
Answer:
- 82.
What is the point of shouldComponentUpdate() method?
Answer:
- 83.
What are forward refs?
Answer:
- 84.
What do these three dots (...) in React do?
Answer:
- 85.
How do you tell React to build in Production mode and what will that do?
Answer:
- 86.
What are typical middleware choices for handling asynchronous calls in Redux?
Answer:
- 87.
What are the lifecycle methods of ReactJS?
Answer:
- 88.
What are the different phases of ReactJS component lifecycle?
Answer:
- 89.
What is Key and benefit of using it in lists?
Answer:
- 90.
What's the difference between an Element and a Component in React?
Answer:
- 91.
What is the difference between ShadowDOM and VirtualDOM?
Answer:
- 92.
Why do class methods need to be bound to a class instance?
Answer:
- 93.
What are stateless components?
Answer:
- 94.
What is ReactDOM?
Answer:
- 95.
What is children prop?
Answer:
- 96.
Why ReactJS uses className over class attribute?
Answer:
- 97.
What are React Hooks?
Answer:
- 98.
What does "shouldComponentUpdate" do and why is it important?
Answer:
- 99.
What's the difference between a "smart" component and a "dumb" component?
Answer:
- 100.
What is the render method for?
Answer:
- 101.
What is Lifting State Up in ReactJS?
Answer:
- 102.
Why should not we update the state directly?
Answer:
- 103.
How to set state with a dynamic key name?
Answer:
- 104.
What's the difference between useRef and createRef?
Answer:
- 105.
What is StrictMode in React?
Answer:
- 106.
What is the alternative of binding this in the constructor?
Answer:
- 107.
What is the difference between createElement and cloneElement?
Answer:
- 108.
What is the point of using keys in React?
Answer:
- 109.
What would be the common mistake of function being called every time the component renders?
Answer:
- 110.
What are advantages of using React Hooks?
Answer:
- 111.
What can you tell me about JSX?
Answer:
- 112.
What is the difference between HTML and React event handling?
Answer:
- 113.
What are error boundaries in ReactJS (16)?
Answer:
- 114.
What is reconciliation in React?
Answer:
- 115.
What are uncontrolled components?
Answer:
- 116.
What is equivalent of the following using React.createElement?
Answer:
- 117.
Given the code defined above, can you identify two problems?
Answer:
- 118.
What is a reducer?
Answer:
- 119.
What is the purpose of super(props)?
Answer:
- 120.
What is "Children"?
Answer:
- 121.
Why would you eject from create-react-app?
Answer:
- 122.
What is the difference between ReactJS and Angular?
Answer:
- 123.
Explain the Virtual DOM concept in React.
Answer:
- 124.
What is the difference between a controlled component and an uncontrolled component?
Answer:
- 125.
Which is preferred option with in callback refs and findDOMNode()?
Answer:
- 126.
What are the recommended ways for static type checking?
Answer:
- 127.
Describe Flux vs MVC?
Answer:
- 128.
Why would you use forceUpdate in a React component?
Answer:
- 129.
What is React Fiber?
Answer:
- 130.
What are some recent changes in the React library (e.g. in version 14, 15)?
Answer:
- 131.
Why does React use SyntheticEvents?
Answer:
- 132.
How would you go about investigating slow React application rendering?
Answer:
- 133.
What's a pure functional component in React?
Answer:
- 134.
What is the second argument that can optionally be passed to setState and what is its purpose?
Answer:
- 135.
When is it important to pass props to super(), and why?
Answer:
- 136.
Do Hooks replace render props and higher-order components?
Answer:
- 137.
Why would you need to bind event handlers to "this"?
Answer:
- 138.
What is the difference between Flow and PropTypes?
Answer:
- 139.
What is the difference between using constructor vs getInitialState in React?
Answer:
- 140.
Why are String Refs legacy?
Answer:
- 141.
Are you familiar with Flux?
Answer:
- 142.
What is the React context?
Answer:
- 143.
Why would you use React.Children.map(props.children, () => ) instead of props.children.map(() => )?
Answer:
- 144.
What is mapStateToProps and mapDispatchToProps?
Answer:
- 145.
How to create props proxy for HOC component?
Answer:
- 146.
How to conditionally add attributes to React components?
Answer:
- 147.
Does React re-render all components and sub components every time setState is called?
Answer:
- 148.
If you need to access the underlying DOM node for a React component, what's the typical way to do this in React?
Answer:
- 149.
How to apply validation on Props in ReactJS?
Answer:
- 150.
When would you use StrictMode component in React?
Answer:
- 151.
What is a Pure Function?
Answer:
- 152.
Explain some difference between Flux and AngularJS (1.x) approach
Answer:
- 153.
What is reselect and how it works?
Answer:
- 154.
What is the key architectural difference between a JavaScript library such as React and a JavaScript framework such as Angular?
Answer:
- 155.
What is Redux Thunk used for?
Answer:
- 156.
What is React Fiber?
Answer:
- 157.
How to use Polymer in ReactJS?
Answer:
- 158.
How to avoid the need for binding in React?
Answer:
- 159.
How does React renderer work exactly when we call setState?
Answer:
- 160.
If you created a React element like Twitter below, what would the component definition of Twitter look like?
Answer:
- 161.
What is wrong with this code?
Answer:
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