Adding an item to multiple lists at once

Imagine you have two lists : - list A - list B

The list A contains multiple list B, I want to be able to add an item to all list B that are contain in the list A in one time. I already make some research about it and i couldn't find any solution for my problem . Thank you.

Solution 1: Ajil O.

Easiest way would be to iterate through the list and add the string you want to add.

List<List<String>> listA = [[], [], [], []]; // I'm assuming your list 
                                             // is something like this

listA.forEach((listB) {
  listB.add('String to be added');
});