Flutter: The null value
In Dart 2.0, the Dart team added null safety to the Dart language. When a variable is
null it is because it does not have any reference to any object, or we can say that it does not have any value.
By default when we create a variable, it cannot have null values. If we try to compile the next code it will fail:
String myName = null;
If we want to create a variable with null support we must add a question mark like this:
String? myName = null;
When should we use a variable with null support?
We should only create a variable with null support when we are 100% sure that it can be
null this will help our IDE to understand if we are trying to assign
null to a variable that is non-null, so we won't be able to compile the app until these errors are fixed.