React Questions

1. What is the purpose of useEffect hook in React?

2. React separates the user interface into components. How are components combinded to create a user interface?

3. . What is [e.target.id] called in this code snippet?

  const handleChange = (e) => {
  setState((prevState) => ({ ...prevState, [e.target.id]: e.target.value }));
}

4. How can you access the state of a component from inside of a member function?

5. React can only render elements in the root document element.

6. Which method in a React Component should you override to stop the component from updating?

7. What is the output of the below code ?

var Geeks=(props)=>
{
 return(
 

DSA Course 1
 

 

DSA Course 2
 

 );
}
ReactDOM.render( < DSA Course/ > ,mountNode)

8. What is the children prop?

9. Using object literal enhancement, you can put values back into an object. When you log person to the console, what is the output?

const name = 'Rachel';
const age = 31;
const person = { name, age };
console.log(person);

10. What can you use to handle code splitting?

11. What is the correct syntax to import a Component from React?

12. Which of the following is NOT a rule for React Hooks?

13.  How many ways of defining your variables in ES6?

14. What will be the output of the following code?

import React, { Component } from 'react';  
const App = () => {  
    
      return(  
          < div >  
             < h1 className = "hello" > {25+20}< /h1 >   
          < /div >  
      );   
}  
export default App;

15.  React.js is written in which of the following language?