Question

I need to develop an application where two csv files are compared. The first file has a list of email addresses. The second list also has email addresses, but includes name and address info. The first list contains email addresses that need to be removed from the second list. I have the Fast CSV reader from the CodeProject site which works pretty well. The application will not have access to a database server. A new file wil be generated with data that is considered verified. Meaning, it will not contain any of the information from the first file.

Answer 1

If you read both lists into collections, you can use Linq to determine the subset of addresses.

Here is a quick example class I whipped up for you.

using System;
using System.Linq;
using System.Collections.Generic;

public class RemoveExample
{
    public List<Item> RemoveAddresses(List<Item> sourceList, List<string> emailAddressesToRemove)
    {
        List<Item> newList = (from s in sourceList
                              where !emailAddressesToRemove.Contains(s.Email)
                              select s).ToList();
        return newList;
    }

    public class Item
    {
        public string Email { get; set; }
        public string Name { get; set; }
        public string Address { get; set; }
    }
}

To use it, read your csv into a List, then pass it, and your list of addresses to remove as a List into the method.