add key

client/src/components/Home/RoomSingle.js

@@ -14,7 +14,7 @@ const INIT_ROOM = {
 const RoomSingle = () => {
   const [room, setRoom] = useState([INIT_ROOM]);
   const [error, setError] = useState("");
-  const channelId = 'main';
+  const channelId = "main";
   const { roomId } = useParams(room.roomId);
   async function getJoinRoom(Id) {
     try {
@@ -45,10 +45,13 @@ const RoomSingle = () => {
       {room &&
         room.map((el) => (
           <div>
-            {room[0] === INIT_ROOM ? (<div></div>): (
+            {room[0] === INIT_ROOM ? (
+              <div></div>
+            ) : (
               <Link
                 to={`/room/${el.roomId}/${channelId}`}
                 className="text-decoration-none text-dark"
+                key={el.roomId}
               >
                 <div
                   className="d-flex mx-4 my-2 p-2"
@@ -74,7 +77,8 @@ const RoomSingle = () => {
                   </div>
                   <div className="ms-auto mt-2"> {el.member}/100 </div>
                 </div>
-            </Link>)}
+              </Link>
+            )}
           </div>
         ))}
     </div>