Linq How to Get Average When all values equals null or 0 ? MVC

Question

When my model has values, i can get the average easily with this code

@Model.Where(a => a.count!= null).Average(a => a.totalday).ToString()

For example:

count = 7 totalday= 3 average= 2.33

But i can't get average value when my model values equals to null or zero. As you know we can't divide 0 to 0 or null to null.

I mean;

count = 0 or null; totalday= 0 or null; average= ????

If all values are null, how can i write my table to "0" or a string like "there is no any average"

I tried lots of things but i get an error.

Answer 1

It really depends on what you want do do. If you're ok with having some sort of default value for the average then you can use DefaultIfEmpty

@Model.Where(a => a.count!= null)
      .Select(a => a.totalday)
      .DefaultIfEmpty(0)
      .Average()
      .ToString()

But if it would be better to display something else entirely then you'll have to first check whether there are any elements in the filtered sequence.