Null check operator used on a null value list

Solution 3: Using Fallback Operator : Here, “str” is null, and we set the fallback operator with fallback value in case of “str” is null. You need to do this before using it on the code. You can use this method to handle Null values to escape the “Null check operator used on a null value” error in Flutter or Dart.

The nullish coalescing operator ( ?? ) is a logical operator that returns its right-hand side operand when its left-hand side operand is null or undefined , and otherwise returns its left-hand side operand .

You can do this in two ways: