Linq and conditional sum

Question

I have a class and a list as below:

class C1
{
    int RecType ...;
    decimal Income ...;
    decimal Outcome ...;
}

List<C1> myList ...;

The list is loaded with several records, and they have various values in RecType What I want is to calculate total on Income and Outcome but only for a certain value of RecType

Here's a pseudo code of what I need to get

totalIncome = myList.Sum(Income).Where(RecType==1);

How can I accomplish this with linq?

Thank you

Mark Rushakoff · Accepted Answer · 2010-06-05T01:38:00.563

46

totalIncome = myList.Where(x => x.RecType == 1).Select(x => x.Income).Sum();

First you filter on the record type (Where); then you transform by Selecting the Income of each object; and finally you Sum it all up.

Or for a slightly more terse version:

totalIncome = myList.Where(x => x.RecType == 1).Sum(x => x.Income);

edited Jun 05 '10 at 01:38

answered Jun 05 '10 at 01:24

Mark Rushakoff

249,864
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score 41 · Answer 2 · answered Jun 05 '10 at 03:01

41

totalIncome = myList.Sum(c=>
    (c.RecType==1 ? c.Income : 0));

answered Jun 05 '10 at 03:01

code4life

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Thanks alot, this seemed to be the only fix for me to get the sum of a nullable decimal. – user1534664 Apr 16 '14 at 20:57
This is awesome! Works with linq to entities and even solves the problem for when the list is empty. – Henrique Miranda Dec 26 '14 at 19:07

Linq and conditional sum

2 Answers2

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