C# list count returning object null

Question

I have the following model in my asp mvc application

 public class StringIntType
 {

    public string str { get; set; }
    public int nbr { get; set; }
    public string par { get; set; }
    public DateTime date { get; set; }
}

I run this query

  var sql = "select object as str , host as par from table " +
            "where date > '2015-01-01' and date <'2015-01-03' option (recompile)";

and map results into this list

var myList = (List<StringIntType>)db.Database.SqlQuery<StringIntType>(sql).ToList();

The problem is when i try to do some sorting in myList that way

 int n = myList.Where(x => x.par.Contains("object")).Count();

I get the following error

Object reference not set to an instance of an object at  x.par.Contains("object")

probably your myList is null thats why. Perform a null check before directly manipulating it — Dhrumil
– Dhrumil, Commented Apr 22, 2015 at 7:03
Provided myList is not null, may be there are rows in your table with 'par' column set to null? — JPG
– JPG, Commented Apr 22, 2015 at 7:04
@JPG that was it some columns are null i should add where columns not null — drex drex
– drex drex, Commented Apr 22, 2015 at 7:09

Peyman · Accepted Answer · 2015-04-22 07:04:18Z

5

cause x.par can be null

So you can do like this:

int n = myList.Where(x => x.par != null && x.par.Contains("object")).Count();

answered Apr 22, 2015 at 7:04

Peyman

3,1361 gold badge21 silver badges32 bronze badges

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

Comments

Philip Song · Accepted Answer · 2015-04-22 07:09:28Z

3

Try setting each x.par to a default value other than null or do a check on x.par for null before calling Contains on it.

answered Apr 22, 2015 at 7:09

Philip Song

313 bronze badges

Comments

Guillaume · Accepted Answer · 2015-04-22 07:03:33Z

2

x or x.par might be null :

int n = myList.Where(x => x != null &&  x.par != null && x.par.Contains("object")).Count();

answered Apr 22, 2015 at 7:03

Guillaume

13.2k3 gold badges44 silver badges49 bronze badges

Collectives™ on Stack Overflow

C# list count returning object null

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related