Flutter: How to initialize an empty list for every Object in an Array?

Question

Hi I'm very new to flutter and coding in general therefore my approach on this might not be the cleanest. Anyways:

I'm storing data in an Array and use the Array-Items to build ListTiles. Now I want to add the possibility to write comments to a Tile and store the input-data like author-name, time and the Comment-Text to the Array/Item. As there aren't any comments in the beginning, every Item should have an empty List of comments to start with. When I initialize the empty list for a single Item it works and I can add TextData to the list. But because my Array is very large I can't initialize the empty list for every single Item. Therefore I'm searching for a way to set the default for every Item to be an empty list without the List being a const List, as I can't add to the const List.

// DataType to store a single comment with further information

class TextData {
  Text({
    this.text,
    this.author,
    this.time,
});
  final String text;
  final String author;
  final time;
}

//All the Data for one ArrayItem including a List of Comments

class Data {
  Data({
    this.data1,
    this.data2,

    this.comments,
  });

  final String data1;
  final String data2;

// List of comments for one ArrayItem

  List<TextData> comments;
}

I don't get any error messages I just can't add to the list if it isn't initialized or its initialized as a default.

I appreciate any Help. Thanks in advance

Answer 1

Why don't you just write that in your Data class:

List<TextData> comments = []

instead of

List<TextData> comments;