Question

Working on a .net 2.0 project and no linq and cannot add any external library.

Build a small example of what I need to do in my real project.

How do you group by eg “Employee.Category” without using linq.

For each group I need to do something about it.

How do you group by in .net 2.0?

     class Program
        {
            static void Main(string[] args)
            {
                List<Employee>employees=new List<Employee>();
                Employee employee = new Employee();
                employee.Id = 1;
                employee.Category = "Management";

                Employee employee2 = new Employee();
                employee.Id = 2;
                employee.Category = "Management";

                Employee employee3 = new Employee();
                employee.Id = 3;
                employee.Category = "Director";

                Employee employee4 = new Employee();
                employee.Id = 4;
                employee.Category = "Worker";

                Employee employee5= new Employee();
                employee.Id = 5;
                employee.Category = "Director";
                Employee employee6 = new Employee();
                employee.Id = 6;
                employee.Category = "Worker";

                employees.AddRange(new Employee[] { employee, employee2, employee3, employee4, employee5, employee6 });

                //1)Group them by category in .net 2.O NO LINQ
                //2)Foreach item in the group do something.

                Console.WriteLine("??");
            }
        }

        public class Employee
        {
            public int Id { get; set; }
            public string Name { get; set; }
            public string Category { get; set; }
        }

Thanks for any suggestions

Answer 1

How about:

Dictionary<string, List<Employee>> groups =
       new Dictionary<string, List<Employee>>();
foreach(Employee emp in employees) {
    List<Employee> group;
    if(!groups.TryGetValue(emp.Category, out group)) {
        group = new List<Employee>();
        groups.Add(emp.Category, group);
    }
    group.Add(emp);
}

foreach(KeyValuePair<string,List<Employee>> pair in groups) {
    Console.WriteLine(pair.Key);
    foreach(Employee emp in pair.Value) {
        Console.WriteLine(emp.Id);
    }
}