How do I use FirstOrDefault?

How do I use FirstOrDefault?

Use the FirstorDefault() method to return the first element of a sequence or a default value if element isn’t there. List val = new List { }; Now, we cannot display the first element, since it is an empty collection. For that, use the FirstorDefault() method to display the default value.

What is first and FirstOrDefault?

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.

What is Entity Framework FirstOrDefault?

First or FirstOrDefault is used when you expect more than one record in the database. This method returns the first matching row from the database. If no records found in the database then First will throw an exception, while FirstOrDefault returns the default value.

What does first or default 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 does FirstOrDefault return if not found?

What is first or FirstOrDefault in Linq?

FirstOrDefault works same as First() does, FirstOrDefault returns the first element from a sequence, but here there is an advantage over First(), so if there is no record in the collection which matches input criteria then FirstOrDefault() can handle null values and it does not throw an exception.

What’s the difference between first ( ) and firstordefault?

The FirstOrDefault() method does the same thing as First() method. The only difference is that it returns default value of the data type of a collection if a collection is empty or doesn’t find any element that satisfies the condition. The following example demonstrates First() method. Example: LINQ First() – C#.

When to use defaultifempty in firstordefault method?

The FirstOrDefault method does not provide a way to specify the default value to return if source is empty. If you want to specify a default value other than default (TSource), use the DefaultIfEmpty (IQueryable , TSource) method as described in the Example section.

How to use firstordefault method in IEnumerable?

The following code example demonstrates how to use FirstOrDefault (IEnumerable , Func ) by passing in a predicate. In the second call to the method, there is no element in the array that satisfies the condition.

When to use firstordefault on an empty sequence?

The IQueryable to return the first element of. default ( TSource) if source is empty; otherwise, the first element in source. source is null. The following code example demonstrates how to use FirstOrDefault (IQueryable ) on an empty sequence. ‘ Create an empty array.