use of First and FirstOrDefault

First() :

When we Use First() in LINQ in Query Syntax Or Method Syntax, At that Time If we Do not Get any Record Corresponding To Expression in Where Clause then It Will Throw You Exception as:

InvalidOperationException: Sequence contains no elements.

FirstORDefault () :

When we Use FirstORDefault () in LINQ in Query Syntax Or Method Syntax, At that Time If we Do not Get any Record Corresponding To Criteria in Where Clause then It Will return Some Default Value (Null).

I would use First() when I know or expect the sequence to have at least one element. In other words, when it is an exceptional occurrence that the sequence is empty.

Use FirstOrDefault() when you know that you will need to check whether there was an element or not. In other words, when it is legal for the sequence to be empty. You should not rely on exception handling for the check. (It is bad practice and might hurt performance).

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Gautam Parmar8y ago
Accepted answer
First() :
When we Use First() in LINQ in Query Syntax Or Method Syntax, At that Time If we Do not Get any Record Corresponding To Expression in Where Clause then It Will Throw You Exception as:

InvalidOperationException: Sequence contains no elements.

FirstORDefault () :
When we Use FirstORDefault () in LINQ in Query Syntax Or Method Syntax, At that Time If we Do not Get any Record Corresponding To Criteria in Where Clause then It Will return Some Default Value (Null).

I would use First() when I know or expect the sequence to have at least one element. In other words, when it is an exceptional occurrence that the sequence is empty.

Use FirstOrDefault() when you know that you will need to check whether there was an element or not. In other words, when it is legal for the sequence to be empty. You should not rely on exception handling for the check. (It is bad practice and might hurt performance).
+1