如何比较具有与第一个列表相同的数据成员之一的字符串列表和对象列表

Question

I have User class and in that data members are

public string userid {get;set;}
public string FirstName {get;set;}
public string LastName  {get;set;}
public string address {get;set;}
public string mobilenumber {get;set;}

I have another list of string which contain only userid in form of string.

I want to compare userid of first list with the string in the second list

What is the LINQ query for that?

If the userid did not match with the string then query should return object present in that list.

Answer 1

I'll assume you have a List<User> called Users and a List<string> called listOfUserIds. Then you can use the following Linq query to get all the Users who's Ids do not exist in listOfUserIds.

Users.Where(user => !listOfUserIds.Any(id => id == user.userid));