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Can a LINQ query return NULL?
7 Answers. It will return an empty enumerable. It wont be null.
Can toList () return NULL?
toList() will return an empty ArrayList . That said, there’s no reason someone couldn’t use a weird Collector to return null in certain circumstances: . of( ArrayList::new, ArrayList::add, (a, b) -> { a.
Can IEnumerable where return NULL?
5 Answers. You do not need to check if selectedRows is null . The returned IEnumerable<> might be empty, but it will never be null .
How do you assign an empty string if the value is NULL in LINQ query?
Empty }; The ?? operator is called the null-coalescing operator and is used to define a default value for nullable value types or reference types. It returns the left-hand operand if the operand is not null; otherwise it returns the right operand.
How do I know if a LINQ query is empty?
if (myQuery. Count > 0) You could also use the Count() method on the original query, but then you would be running the query twice, once to count the items, and once to use them. LINQ queries should never return null and you should not get an exception if the result is empty.
Can FirstOrDefault return null?
8 Answers. FirstOrDefault returns the default value of a type if no item matches the predicate. For reference types that is null . Thats the reason for the exception.
Does first return null?
The major difference between First and FirstOrDefault is that First() will throw an exception if there is no result data for the supplied criteria whereas FirstOrDefault() returns a default value (null) if there is no result data. First() will throw an exception if there is no result data, as you can see below.
Is it better to return null or empty list?
It is better to return empty collections rather than null when writing methods. The reason being that any code calling your method then doesn’t need to explicitly handle a special null case. Returning an empty collection makes the null check redundant and results in much cleaner method calling code.
What does FirstOrDefault return if not found?
FirstOrDefault returns the default value of a type if no item matches the predicate. For reference types that is null . Thats the reason for the exception.
What is difference between SingleOrDefault and FirstOrDefault?
between the two. Semantical Difference: FirstOrDefault returns a first item of potentially multiple (or default if none exists). SingleOrDefault assumes that there is a single item and returns it (or default if none exists).