dart classes

The fields within a dart class are non-nullable unless its stated explicity with a ?. The following code is fine:

class SomeOne {
  String? name;
  int? age;
}

But the moment you delete the ? marks, LSP will complain its a non-nullable field and it must be initialized. This is important to keep in mind as we model stuff as dart classes. 😀

But when we declare fields as final, its not the null-safety rules, but by virtue of being final that we gotta intialize the fields.

Since final fields need to be initialized before the class gets instantiated, they need to initialized BEFORE the constructor gets called. This is where initializer lists comes in:

But we've gotta a shorthand for initializer list:

Upate 2024-03-02 10:24AM

I no longer think this can be considered an equivalent to initializer list. The below code just forces you to create an object of the class specifiying arguments, whereas with initializer list you can check whether arguments are null (not passed to the constructor) and set them approrpriate values.

Yeah. So I no longer think below is a shorthand for initializer list:

With the above definition of constructor, we're gonna have to initialize the class with positional parameter: var thisOne = SomeOne('Vector', 29). This isn't as verbose as I would like it to be. This is where named arguments and {} come into play:

But unlike positional paramaters, the parameters within {} are optional, so nullable. This is the errors are raised. This is were required keyword comes to play. When named parameters (those within {}) refer to fields that are non-nullable, you need to preprend required before this.

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