Warning: Each child in a list should have a unique “key” prop.
Jul 23, 2021
Material UI⁴.11, React¹⁷.0.2, Created at July 21, 2021, Read Series…
React uses the
keyprop to understand the component-to-DOM Element relation, which is then used for the reconciliation process. It is therefore very important that the key always remains unique, otherwise there is a good chance React will mix up the elements and mutate the incorrect one. It is also important that these keys remain static throughout all re-renders in order to maintain best performance.
/* Fix of Warning: Each child in a list should have a unique "key" prop. in App.tsx */<React.Fragment key={lng}>
{lng},
</React.Fragment>Or/* Fix of Warning: Each child in a list should have a unique "key" prop. in LodashGroupByList.tsx */<AccordionDetails key={item.key}>
...
</AccordionDetails>
Github commits is here: Basic-1.13. 2 Popular React Warnings
