如何从C＃列表中的记录中仅获取一个值？

Question

I have two custom list:

List<Detailsofemployee> empDetails = new List<Detailsofemployee>();
List<regionDetails> regDetails = new List<regionDetails>();

• empDetails have values {"1","Sam","IT"} .
• regDetails have values {"IT","UK"} .

I want to get the data from first list and based on that i want to get data from another list

var det = (from l in empDetails where l.ID == "1" select l.Department)
var region = (from l in regDetails where l.Department == det select l.Country)

How can I get det = "IT" ?

Answer 1

with checking and user input value

using System.Linq;

var userInputId = //user input value
var emp = empDetails.FirstOrDefault(x => x.Id == userInputId);
var regDetail = new regionDetails();
if (emp != null)
{
   regDetail =  regDetails.FirstOrDefault(c => c.Department == emp.Department);
}
if (regDetail != null)
{
    return regDetail.Country;
}