The body might complete normally, causing 'null' to be returned, but the return type, 'Widget'

[Ange0]

Hello guys,
I had trouble implementing this code when I copied and pasted it into project, so I added some code snippets to make it work for me.
// befor

RatingBar.builder(
initialRating: 3,
itemCount: 5,
itemBuilder: (context, index) {
switch (index) {
case 0:
return Icon(
Icons.sentiment_very_dissatisfied,
color: Colors.red,
);
case 1:
return Icon(
Icons.sentiment_dissatisfied,
color: Colors.redAccent,
);
case 2:
return Icon(
Icons.sentiment_neutral,
color: Colors.amber,
);
case 3:
return Icon(
Icons.sentiment_satisfied,
color: Colors.lightGreen,
);
case 4:
return Icon(
Icons.sentiment_very_satisfied,
color: Colors.green,
);
}
},
onRatingUpdate: (rating) {
print(rating);
},
;

// after

RatingBar.builder(
initialRating: 3,
itemCount: 5,
itemBuilder: (context, index) {
switch (index) {
case 0:
return Icon(
Icons.sentiment_very_dissatisfied,
color: Colors.red,
);
case 1:
return Icon(
Icons.sentiment_dissatisfied,
color: Colors.redAccent,
);
case 2:
return Icon(
Icons.sentiment_neutral,
color: Colors.amber,
);
case 3:
return Icon(
Icons.sentiment_satisfied,
color: Colors.lightGreen,
);
case 4:
return Icon(
Icons.sentiment_very_satisfied,
color: Colors.green,
);
}
return Container();
},
onRatingUpdate: (rating) {
print(rating);
},
)

[ghassenbenzahra123]

@Ange0 the builder function requires a widget to return. In this case, you are returning the widget but it is in a switch statement. This means that if the switch statement didn't satisfy, your builder will return null which is not acceptable.

You can fix it by just adding a default case for the switch statement like this:
default: return const SizedBox();