Late in Dart and Flutter

In my previous article on sound null safety of Flutter and Dart, I simply forgot to discuss another keyword “late”.

Better late than never. 🙂

In the lib folder of my Dart console application, I have this code.

class Name {
  late String _name;
  String get getName => _name;
  set setName(String aValue) => _name = aValue;
}

And in the bin folder in main dart file I instantiate the Name object this way:

var name = Name();
  name.setName = 'Sanjib';
  print(name.getName);

As expected, it gives the expected output : Sanjib.

However, what does that line mean?

late String _name;

It means, the Dart compiler keeps its faith on us that, we’ll never allow this private property to be null.

Is that real?

Oh, yes.

If we had assigned a null value, instead of assigning a String, it would give us an error.

Because, the compiler enforces that the value should be non-nullable.

In Flutter, the “late” keyword has other advantages though.

We’ll discuss that in the next article.

What Next?