Question

Is there a quick way to say

Where (data.x == (If notempty x = y else x = default))

Assuming the data being compared is both strings

Compare listitem.string with passed.string - if passed.string isnotempty, else passed.string equals default value.

in a Linq ‘where` query.

Apologies that the question was really badly written.

… As per the comments updated …

Answer 1

Ok, with your clarifications to the original post, I think I see what you’re getting at now.

Try the following clause (where data.x is your current element and y in the passed argument).

where y == (string.IsNullOrEmpty(y) ? "default" : data.x)

I do not believe it’s possible to use the null coalescing operator here, since the variables you are comparing and returning are different.

Old Post:
If what is empty? I’m guessing you’re referring to y.

For a generic type T, you could use the following clause:

where data.x == (y ?? DefaultValue<T>())

where DefaultValue is a generic function of T that returns a so-called “default” value.