Check if firstordefault null

If you want the behaviour you are talking about you need to use DefaultIfEmpty [ docs here ] and supply the default object you want back in the case of an empty sequence.

Some use cases may call for this, but with a default value different from null: have a look at this stackoverflow question I asked some while ago, answers to which helped me tremendously afterwards.

It is the stick your head in the sand method. SingleOrDefault can be an acceptable usage. When i find myself needing First or Single i always create extension methods that allow me to do dollarDollarBills. Is that so? But playing along if children. Any return children. This is actually a great illustration of my point.

You are likely in a vastly different scenario for a person who has children vs a person who has none. Your solution would require to go to the server 2 times instead of 1. I digress, your statement does not apply to how i build software.

I am extremely greedy when it comes to data. Privacy policy. Thank you. Microsoft makes no warranties, express or implied, with respect to the information provided here. Returns the first element of a sequence, or a default value if the sequence contains no elements. Returns the first element of the sequence that satisfies a condition or a default value if no such element is found.

Returns the first element of a sequence, or a specified default value if the sequence contains no elements. FirstOrDefault ; This projects the results into a collection of nullable ints, and if that is empty no results you get a null -- there's no way you can mistake that for the int that a successful search would yield. Jon Jon k 74 74 gold badges silver badges bronze badges. The first option doesn't work for non-nullable types as the key — KingOfHypocrites. KingOfHypocrites just check for the default value of that type Emerson Cardoso Emerson Cardoso 3 3 silver badges 5 5 bronze badges.

The clearest code I think is this: if dict. Yusuf Demirag Yusuf Demirag 7 7 silver badges 10 10 bronze badges. What happens if the value generic type is a non-nullable? Good point, in that case we would need to compare the default value of that type.

In my case value type was nullable. Since you're using Linq anyway, what's wrong with using. Luke Alderton Luke Alderton 2, 1 1 gold badge 21 21 silver badges 33 33 bronze badges. Smagin Alexey Smagin Alexey 1 1 silver badge 6 6 bronze badges. Vlad Hrona Vlad Hrona 1 1 silver badge 5 5 bronze badges. For example, a dictionary with int keys where 0 might be one of the keys. Sign up or log in Sign up using Google. MeterReadingDone : String.

FirstOrDefault Error: CS Type of conditional expression cannot be determined because there is no implicit conversion between 'System. Bulk Delete. Bulk Update. Bulk Merge.

FirstOrDefault might be null no corresponding record. Ivan Stoev. DefaultIfEmpty defaultElement. FirstOrDefault ; This won't lead to a performance penalty! After the DefaultIfEmpty you only take the first element, which is what you want.