c# list find duplicate update multiple lists

Question

I have 3 lists lstTicketType, lstQuantity lstAmount. I am trying to merge ticket types and update the other two lists accordingly

The data is as follows

lstTicketType | lstQuantity | lstAmount
---------------------------------------
Standard      |     1       |   8:5
Standard      |     1       |   8.5
Student       |     1       |   6.5
Student       |     1       |   6.5
Senior        |     1       |    4

I am able to find the duplicates by using

      var query = lstTicketType.GroupBy(x => x)
      .Where(g => g.Count() > 1)
      .Select(y => new { Counter = y.Count() })
      .ToList();

how do i update the list so that it looks like

lstTicketType | lstQuantity | lstAmount
---------------------------------------
Standard      |     2       |    17
Student       |     2       |    13
Senior        |     1       |    4

Answer 1

hi your answer is the under code

List<string> lstTicketType = new List<string>() { "Standard", "Standard", "Student", "Student", "Senior" };
        List<int> lstQuantity = new List<int>() { 1,1,1,1,1};
        List<double> lstAmount = new List<double>() {8.5 , 8.5 , 6.5 , 6.5 ,4};

        List<mergeClass> LstMC = new List<mergeClass>();

        for (int i = 0; i < lstTicketType.Count(); i++)
        {
            mergeClass NewMC = new mergeClass(lstTicketType[i], lstQuantity[i], lstAmount[i]);
            LstMC.Add(NewMC);
        }
        var query=LstMC.GroupBy(q=>q.TicketType)
                    .Select(q=>new{TicketType=q.First().TicketType,
                                    Quantity=q.Sum(a=>a.Quantity),
                                    Amount=q.Sum(a=>a.Amount)
                    }).ToList();

and you must create under class in your project

 public class mergeClass
{
    public string TicketType { set; get; }
    public int Quantity { set; get; }
    public double Amount { set; get; }
    public mergeClass(string T, int Q, double A)
    {
        TicketType = T;
        Quantity = Q;
        Amount = A;
    }

}

Answer 2

List<Ticket> tickets = new List<Ticket>()
            {
                new Ticket(){
                    TicketType="Standard",
                    Quantity =1,
                    Amout= 8.5M
                },
                new Ticket(){
                    TicketType="Standard",
                    Quantity =1,
                    Amout= 8.5M
                },
                new Ticket(){
                    TicketType="Student",
                    Quantity =1,
                    Amout= 6.5M
                },
                new Ticket(){
                    TicketType="Student",
                    Quantity =1,
                    Amout= 6.5M
                },
                new Ticket(){
                    TicketType="Senior",
                    Quantity =1,
                    Amout=4M
                },
            };

            var groupTicket = tickets.GroupBy(p => p.TicketType).Select(t => new
            {
                TicketType = t.Key,
                Quantity = t.Sum(x => x.Quantity),
                Amount = t.Sum(x => x.Amout)
            }).ToList();

Answer 3

Try using "Sum". Don't rely on one my answer and try to write your own code to understand how it works. Otherwise, you will never know how to code. This is my reference - https://stackoverflow.com/a/16522841/1554116

internal class Ticket
{
    public string TicketType { get; set; }
    public int Quantity { get; set; }
    public decimal Amount { get; set; }
}
internal class Program
{
    private static void Main(string[] args)
    {
        var list = new List<Ticket>();
        list.Add(new Ticket() { TicketType = "Standard", Quantity = 1, Amount = 8.5m });
        list.Add(new Ticket() { TicketType = "Standard", Quantity = 1, Amount = 8.5m });
        list.Add(new Ticket() { TicketType = "Student", Quantity = 1, Amount = 6.5m });
        list.Add(new Ticket() { TicketType = "Student", Quantity = 1, Amount = 6.5m });
        list.Add(new Ticket() { TicketType = "Senior", Quantity = 1, Amount = 4m });

        foreach (var item in list)
        {
            System.Console.WriteLine($"TicketType: {item.TicketType}, Quantity: {item.Quantity}, Amount: {item.Amount}");
        }

        System.Console.WriteLine("------------------------------------------");

        list = list.GroupBy(x => x.TicketType).Select(x => new Ticket()
        {
            TicketType = x.First().TicketType,
            Quantity = x.Sum(y => y.Quantity),
            Amount = x.Sum(y => y.Amount)
        }).ToList();

        foreach (var item in list)
        {
            System.Console.WriteLine($"TicketType: {item.TicketType}, Quantity: {item.Quantity}, Amount: {item.Amount}");
        }

        System.Console.Read();
    }
 }