Can I Have an Incrementing Count Variable in Linq?
I Want to Do Something Like This: from a in Stuff Let Counter = 0 Select New { Count = Counter++, A. Name }; but I Get a Error Telling Me That Counter Is Read...
I want to do something like this:
from a in stuff
let counter = 0
select new { count = counter++, a.Name };
But I get a error telling me that counter is read only. Is there a way to do something similar to this, without declaring a variable outside of the query?
Basically, I just want to show a count/index column in LINQPad (which is awesome, BTW), which means I can't declare counter ahead of time.
3 Answers
Rather than using side-effects, use the overload of Select which takes an index:
stuff.Select((value, index) => new { index, value.Name });
You could do it using side-effects, but not in the way you tried:
int counter = 0;
var query = from a in stuff
select new { count = counter++, a.Name };
I would strongly advise against this though.
If you truly want it to be a counter, and not just an index, then just move the counter declaration outside the LINQ expression
var counter = 0;
from a in stuff
select new { count = counter++; a.Name };
Just add two variable here NumberRow is for that
.Select((x,NumberRow) => new ViewModelArchiveOrder
{
NumberRow= NumberRow + 1,
})
David Miller brings 15 years of experience in global economics, personal finance strategy, and market dynamics. He specializes in turning complex economic trends into actionable insights for everyday readers.
