> we just use the index from the .map() loop to add a key to every element
Doing this could hide weird bugs. Let's say we render a list of posts with "remove" button for each one. The user clicks on "remove" button, we modify the underlying this.state.posts. And on next re-render removed post key would be assigned to the next post! The next post could inherit just-deleted post handlers, for example.
It's much better to use unique keys like database ids.
Doing this could hide weird bugs. Let's say we render a list of posts with "remove" button for each one. The user clicks on "remove" button, we modify the underlying this.state.posts. And on next re-render removed post key would be assigned to the next post! The next post could inherit just-deleted post handlers, for example.
It's much better to use unique keys like database ids.