flutter - Compare 2 different list and filter the first list

Question

Trying to achieve the below result but not able to find the correct process or code to resolve it. Please find any solution.

List ids = ['2330', '1111'];
List users = [{"id": ['1234','2330'], "name": "username1"}, {"id":['1111','2330'], "name": "username2"},{"id": ['3455','2331'], "name": "username3"}];
# I want the result to be like
List selectedUsers = [{"id": ['1234','2330'], "name": "username1"}, {"id":['1111','2330'], "name": "username2"}];

I tried this...

 List selectedUsers = users.where((u) => ids.contains(u["id"])).toList();

But that doesn't work...

 Result: []

What am I doing wrong?

Thanks in advance!

question from:https://stackoverflow.com/questions/65833919/compare-2-different-list-and-filter-the-first-list

Answer 1

Your code is slightly wrong. You are checking if ids contains the whole list u["id"].

Try this:

List selectedUsers = users.where((u) => ids.any((id) => u["id"].contains(id))).toList();

ids.any(...) takes a function as a test and returns true if any element of the iterable ids passes the test. Here, your test should return true if any of the id from ids appear in u["id"]. Now using this whole thing as your filter, you get the desired result:

[{id: [1234, 2330], name: username1}, {id: [1111, 2330], name: username2}]