Keys help React to identify items which have changed, added, or removed. Keys should be given to the elements inside the array to give the elements a stable identity. The key should be unique. Mostly data will come with as an id and we can use id as key. If we do not pass key to React during mapping it raises a warning on the browser. If the data does not have an id we have to find a way to create a unique identifier for each element when we map it. See the following example:
Keys help React to identify items which have been changed, added, or removed. Keys should be given to the elements inside the array to give the elements a stable identity. The key should be unique. Mostly data will come with as an id and we can use id as key. If we do not pass key to React during mapping it raises a warning on the browser. If the data does not have an id we have to find a way to create a unique identifier for each element when we map it. See the following example: