Get an list of lists with multiple attributes an obtain a new list with a specific attribute in C#-CodePudding

I have a problem manipulating lists and I don´t remember very well how to do this...

            var allUsers = _userService.GetAll();

            List<string> result = new List<string>();

The var allUsers gets a list of a lists with this format

-> [[UserName1,X1,Y1],[UserName2,X2,Y2],...]

Note: I also have a db context when I can get a List of Users with Usernames but i need to put that to a new list() as well but i dont remember the methods to do that too

the result is a new List when im try to put all UserNames

-> [UserName1,UserName2,...]

How I do that in C# and if I call a table of any database will be the same??

Ps: I apologize if there are any spelling mistakes and if the question is very simple to answer that it becomes repetitive

CodePudding user response：

You will want to use AddRange of List<T> in conjunction with the Select method found in the System.Linq assembly.

result.AddRange(allUsers.Select(u => u.Username));

or simply

var result = allUsers.Select(u => u.Username).ToList();