Check out example codes for "find common elements in two flutter". It will help you in understanding the concepts better.

Code Example 1

void main() {
  List l1 = [1, 2, 3, 55, 7, 99, 21];
  List l2 = [1, 4, 7, 65, 99, 20, 21];
  List l3 = [0, 2, 6, 7, 21, 99, 26];

  l1.removeWhere((item) => !l2.contains(item));
  l1.removeWhere((item) => !l3.contains(item));

  print(l1);
}

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