Summarize list by property

Question

I have a list of objects like this:

List list = new List();
list.Add(new ClassName()
{
    Name = 1,
    Amount = 5
});
list.Ad         


        

Answer 1

Do it via LINQ:

var result = list.GroupBy(x => x.Name)
    .Select(x => new ClassName { Name = x.Key, Amount = x.Sum(i => i.Amount) })
    .ToList();

Read more about LINQ here: http://code.msdn.microsoft.com/101-LINQ-Samples-3fb9811b