React How and why to use keys in React Basic Example
Example
For a class-less React component:
function SomeComponent(props){
const ITEMS = ['cat', 'dog', 'rat']
function getItemsList(){
return ITEMS.map(item => <li key={item}>{item}</i>);
}
return (
<ul>
{getItemsList()}
</ul>
);
}
For this example, the above component resolves to:
<ul>
<li key='cat'>cat</li>
<li key='dog'>dog</li>
<li key='rat'>rat</li>
<ul>
