<VirtualizedList

// Use keyExtractor to help the list optimize performance

    keyExtractor={item => item.id}

    data={data}

    initialNumToRender={7}

    renderItem={({item})=> {

        return <Text>{item.name}</Text>;

    }}

// the virtualized list doesn't know how you want to extract your data

// you need to tell it

    getItem={(data, index) => {

        const dataIndex = data.allIds[index];

        return data.byId[dataIndex];

    }}

// it also needs to know how much data you have

    getItemCount={data => data.allIds.length}

/>