How do I use keys in React lists?

How do I use keys in React lists?

In React, keys help identify which items have changed, are added, or are removed. They should be unique among siblings.

Can you give me an example of using keys in a list?

Sure! When rendering a list of items, you can use the map function and assign a unique key to each item like this:

const items = ['Apple', 'Banana', 'Cherry'];

const itemList = items.map((item, index) => (
  <li key={index}>{item}</li>
));

Is it okay to use the index as a key?

Using the index as a key is not recommended if the list can change, as it can lead to issues with component state. It's better to use a unique identifier.

What happens if I don't use keys?

If you don't use keys, React may have trouble identifying which items have changed, leading to inefficient updates and potential bugs.