• +91 9723535972
  • info@interviewmaterial.com

ReactJS Interview Questions and Answers

Related Subjects

Question - What are keys in React?

Answer -

A key is a special string attribute that needs to be included when using lists of elements.
Example of a list using key -

const ids = [1,2,3,4,5];
const listElements = ids.map((id)=>{
return(
  •   {id}
    )
    })
    Importance of keys -

    • Keys help react identify which elements were added, changed or removed.
    • Keys should be given to array elements for providing a unique identity for each element.
    • Without keys, React does not understand the order or uniqueness of each element.
    • With keys, React has an idea of which particular element was deleted, edited, and added.
    • Keys are generally used for displaying a list of data coming from an API.

    Comment(S)

    Show all Coment

    Leave a Comment




    NCERT Solutions

     

    Share your email for latest updates

    Name:
    Email:

    Our partners