List c# distinct by item and sum other items

Question

Imagine a list of objects:

public class Foo
{
    public string Name {get; set;}
    public int Total {get; set;}
}

And now, my list contains 3 objects:

new Foo {Name="object", Total=3};
new Foo {Name="object", Total=7};
new Foo {Name="object", Total=5};

How to distinct by the name and sum the totals? ie The List will have just one object:

new Foo {Name="object", Total=15};

Thanks in advance!

Answer 1

You can do this:

var newTotalList = yourList.GroupBy(x => x.Name)
    .Select(x => new
        {
            Name = x.Key,
            Total = x.Sum(y => y.Total)
        })
    .ToList();

What this code does is, simply, first group the elements by name, and then sum the Total fields of all the elements inside the group.

Answer 2

You should be able to use grouping.

var groupedList = (from ol in objectList

                    group ol by ol.Name
                        into grp
                        select new foo
                        {
                            Name = grp.Key,
                            Total= grp.Sum(ex => ex.Total),
                            City = grp.Select(ex => ex.City).FirstOrDefault(),
                            Country = grp.Select(ex => ex.Country ).FirstOrDefault(),
                            Phone = grp.Select(ex => ex.Phone).FirstOrDefault()
                        }
    ).ToList();

Answer 3

Try this:

List<Object> list = ... // make a list somehow
var totalsPerName = list
    .GroupBy(o => o.Name)
    .Select(group => new Object { Name = group.Key, Total = group.Sum(o => o.Total) })

Answer 4

You can group by Name and then just sum up by Total :

var l = new List<Object>
{
    new Object {Name="object", Total=3},
    new Object {Name="object", Total=7},
    new Object {Name="object", Total=5}
};

var result = l.GroupBy(o => o.Name)
              .Select (grp => new Object 
                            { 
                                Name = grp.Key, 
                                Total = grp.Sum(o => o.Total)
                            });

result is now:

Answer 5

Group your elements by Name, and then for each group, select a new object whose name is name value grouped by for this group, and Total is the sum of all Totals in the group:

var groupdObject =list
    .GroupBy(o =>o.Name)
    .Select(g => 
       new 
       {
         Name = g.Key, 
         Total = g.Sum(o=>o.Total)
       });