CODEWITHSUNDEEP
flutterdart
ali ALI
ali ALI

Reputation: 1

Null check operator used on a null value?

**======== Exception caught by widgets library ======================================================= The following _CastError was thrown building Builder: Null check operator used on a null value **

productmodel.dart
  final List? size;

main.dart
final Product? product;
List _sizeList=[];

`if(widget.product.size!.isNotEmpty){`
`_sizeList=widget.product.size!;`
`}`
       Container(
                                height: 80,
                                child: ListView.builder(
                                    scrollDirection: Axis.horizontal,
                                itemCount: _sizeList!.length,
                                  itemBuilder: (context,index){
                                    print(_sizeList![index]);
                                    return Text(_sizeList![index]);
                                }),
                              ),

Upvotes: 0

Views: 751

Answers (1)

Liliia
Liliia

Reputation: 71

You use null-assertion operator (1). For example here:

`if(widget.product.size!.isNotEmpty){`

It means, that you are sure, that property size isn't null. But in some place in your code variable appears to be null, and you have corresponding error

Upvotes: 1

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