How to return null when the Linq query returns empty value?

Question

I have the following code to get values from the list.

GetList().SingleOrDefault(x => x.Key == "MyKey").MyValue;

When there is Key property with value MyKey in a list it is working fine but when there is not Key property with value MyKey in a list it is throwing an NullReferenceException. How can I return null value instead of exception.

System.NullReferenceException
  HResult=0x80004003
  Message=Object reference not set to an instance of an object.

Kiran Shahi · Accepted Answer · 2018-08-28 04:42:02Z

7

Use ?. and ?[] null-conditional Operators. It tests the value of the left-hand operand for null before performing a member access (?.) or index (?[]) operation; returns null if the left-hand operand evaluates to null.

GetList().SingleOrDefault(x => x.Key == "MyKey")?.MyValue;

edited Aug 28, 2018 at 4:42

Kiran Shahi

8,0109 gold badges41 silver badges77 bronze badges

answered Aug 28, 2018 at 4:35

Access Denied

9,5914 gold badges47 silver badges80 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Prem · Accepted Answer · 2018-08-28 04:47:54Z

2

You can use below code

var result = GetList().SingleOrDefault(x => x.Key == "MyKey");
if(result != null)
{
  //Add your logic
}

answered Aug 28, 2018 at 4:47

Prem

3012 silver badges10 bronze badges

Comments

Kalpesh Rajai · Accepted Answer · 2018-08-28 04:51:12Z

1

More safe way to handle the Null in the LINQ.

GetList().Where(x => x.Key == "MyKey").Select(S=>S.MyValue).SingleOrDefault();

answered Aug 28, 2018 at 4:51

Kalpesh Rajai

2,05628 silver badges41 bronze badges

1 Comment

Kiran Shahi Over a year ago

Hi Kalpesh can you explain how this code handle the null exception

Collectives™ on Stack Overflow

How to return null when the Linq query returns empty value?

3 Answers 3

Comments

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related