Summing similar values with a list using Linq

Question

I have the following value in a list by

Feb 13  100 
Feb 13  150 
Feb 13  127 
Feb 14  50

using linq how do I return another list with the sum for each date including the previous days total?

e.g

Feb 13 357  (Sum of Feb 13)   
Feb 14 407  (Sum of Feb 14 + Sum of Feb 13)

with some mucking about

list= list.OrderBy(i => i.date)
                    .Distinct().Select(
                i =>
                    {
                        np+= i.rh;
                        nh+= i.hm;
                        return new Po
                            {
                                date= i.date,
                                NH =  nh,

                            };
                    }).ToList();

this return this list:

Feb 13  100 
Feb 13  250 
Feb 13  377 
Feb 14  427

I would like just

 Feb 13 357  
 Feb 14 407

Have you tried something already that we could discuss? Or you are waiting for someone else writing the code for you? — Darin Dimitrov, Feb 14 '13 at 17:56

score 3 · Accepted Answer · answered Feb 14 '13 at 18:31

3

decimal runningTotal = 0;
var result = from item in items
             orderby item.Date
             group items by item.Date into grp
             let sum = items.Where(x => x.Date == grp.Key).Sum(x => x.Amount)
             select new
             {
                 Date = grp.Key,
                 Sum = runningTotal += sum,
             };

answered Feb 14 '13 at 18:31

david.s

11,283
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Thank you!!! Happy Valentine day lol. – Fabii Feb 14 '13 at 18:55

score 0 · Answer 2 · answered Feb 14 '13 at 17:59

0

you can try something like this if you know the values ahead

   var Total = listval.Sum(od => od.vall)+listval.where(od => od.date=="Feb 13").Sum(od =>
 od.vall)+listval.where(od => od.date=="Feb 14").Sum(od => od.vall);

answered Feb 14 '13 at 17:59

COLD TOLD

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score 0 · Answer 3 · answered Feb 14 '13 at 18:08

0

You can do so by grouping the objects and using the Sum within the group. The link Mark posted shows exactly how to do that.

answered Feb 14 '13 at 18:08

Mathieson

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Summing similar values with a list using Linq

3 Answers3