using System;

using System.Collections.Generic;

using System.Linq;

​

public class Program

{

    // SEE: https://stackoverflow.com/q/10018957/1016343

​

    //If you have:

    class myClass {

        public int ID; public string FirstName; public string LastName;

    }

​

​

    public static void Main()

    {

​

        //and assigned some values to results as follows: 

        var results=new List<myClass> {

            new myClass()  { ID=1, FirstName="Bill", LastName="Smith" },

            new myClass()  { ID=2, FirstName="John", LastName="Wilson" },

            new myClass()  { ID=3, FirstName="Doug", LastName="Berg" },

            new myClass()  { ID=4, FirstName="Bill", LastName="Wilson" },

            new myClass()  { ID=5, FirstName="Liv", LastName="Dunham" },

        };

        //Then you can define a list of IDs to remove:

        var removeList = new List<int>() { 2, 3 };

​

        Console.WriteLine("\nBefore:");

        foreach(var x in results) {

            Console.WriteLine(x.FirstName + " " + x.LastName);

        }

        //And simply use this to remove them:

        results.RemoveAll(r => removeList.Any(a => a==r.ID));

        // Usage for removal of single items:

        results.RemoveAll(r => r.ID==4);

        // use a local function for special tasks (.NET 5)

        void myRemove()  =>  results.RemoveAll(r => results[^1].FirstName == r.FirstName); 

        myRemove(); // and call it

        Console.WriteLine("\nAfter:");

        foreach(var x in results) {

            Console.WriteLine(x.FirstName + " " + x.LastName);

        }

​

    }

}