type 'Null' is not a subtype of type 'String' in flutter

Question

Widget build(BuildContext context) {
final routeArgs =
    ModalRoute.of(context).settings.arguments as Map<String, String>;
final categoryTitle = routeArgs['title'];
final categoryId = routeArgs['id'];
return Scaffold(
  appBar: AppBar(
    title: Text(categoryTitle),
  ),

Please help me with this This is the error I'm facing with

Answer 1

i think your routeArgs['title'] is null and when you put it in text it is generating error try

Text(categoryTitle??"")