ReactJs: Lifecycle & State
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Total 20 question (100 marks)
1. What command is used to start the React local development server?
2. At the highest level, React components have lifecycle events that fall into.
3. props in react can________.
4. What is the smallest building block of ReactJS?
5. React can only render elements in the root document element.
6. What happens when the following render() method executes? render(){ let langs = ["Ruby","ES6","Scala"] return (<div>
7. How can you optimze performance for a function component that always renders the same way?
8. What type of element will be rendered from the following code? function Hello() { return <h1>Hello reactjs</h1>; } ReactDOM.render(<Hello />, document.getElementById('root'));
9. React separates the user interface into components. How are components combined to create a user interface?
10. When rendering a list using the JavaScript map() method, what is required for each element rendered?
11. What is the default local host port that a React development server uses?
12. React keeps track of what items have changed, been added, or been removed from a list using ________.
13. What is the children prop?
14. To develop and run React code, Node.js is required.
15. In JSX most of the errors can be caught during _________.
16. How can we prevent default behavior in React? What method you can call?
17. If you want to import just the Component from the React library, what syntax do you use?
18. Invoked once, only on the client, after rendering occurs.
19. JSX is faster because it performs ____________ while compiling code to JavaScript
20. What tool does React use to compile JSX?
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