Flutter Getx: initial value of obs variable set to null

Upon now I always use getx observable declarations like this:

var someString = ''.obs;
var someNumber = 0.obs;

and so on...

But what if some variables don't have an initial value at first, and I actually want them to be null and later change them?

Solution 1:

For non null-safe (pre Dart 2.12), you can declare your observable variables like this:

final someVariable = Rx<Type>();

For example:

final someString = Rx<String>();
final someNumber = Rx<int>();

And for null-safety (Dart 2.12 or later), Just use Rxn<Type> instead of Rx<Type>.

For example:

final someString = Rxn<String>();
final someNumber = Rxn<int>();