I´m working on React Native , and i don´t understand this diference to make a setState-CodePudding

export interface Location{
    latitude: number;
    longitude: number;
}

const [routeLines, setRouteLines] = useState<Location []>([]);

When I use setRouteLines( routes => [...routes, location]) works, but I try this setRouteLines([...routeLines, location])doesn't works. I don´t understand the difference.

CodePudding user response：

In your case, the answer might be because using the routeLines for the previous value is not accurate.

React might do something called Batch when states change over time.

As a result, using the callback in setState will guaruntee you are using the most recent state to make updates.