Use ToLookup to search object property : ToLookup : LINQ C# Source Code

    
 

using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
public class Employee {
    public int birthYear;
    public string firstName;
    public string lastName;

    public static Employee[] GetEmployees() {
        Employee[] actors = new Employee[] {
       new Employee { birthYear = 1964, firstName = "K", lastName = "R" },
       new Employee { birthYear = 1968, firstName = "O", lastName = "W" },
       new Employee { birthYear = 1960, firstName = "J", lastName = "S" },
       new Employee { birthYear = 1964, firstName = "S", lastName = "B" },
    };

        return (actors);
    }
}
public class MainClass {
    public static void Main() {
        ILookup<int, Employee> lookup = Employee.GetEmployees().ToLookup(k => k.birthYear);
        IEnumerable<Employee> actors = lookup[1964];
        foreach (var actor in actors)
            Console.WriteLine("{0} {1}", actor.firstName, actor.lastName);
    }
}