React allows you to pass a collection of React elements or components as children in the form of an array. For instance:

   <ul> 
      {[ 
         <li key={0}>One</li>, 
         <li key={1}>Two</li>, 
      ]} 
   </ul> 

Collections of React elements or components must be given a special props property named key. This property lets React know which of the elements in the collection have changed, moved, or been removed in/from the array when an update occurs.