Passing type 'var' into a method in C# [duplicate]

Question

I have some sub queries which are of data type var. These are getting working on a data table. I would like to pass these into another method, how can i do that? Ex:

    var subquery1= from results in table.AsEnumerable()
               where //some condition
               select new
               {
                  column1=results.field1,
                  column2 = results.field2
                  etc.,
               }
     var subquery2= from results in table.AsEnumerable()
               where //different condition
               select new
               {
                  column1=results.field1,
                  column2 = results.field2
                  etc.,
               }

Now, I would like to define some method to pass these subquery1, subquery2 as variables. ex:

void updategrid(var queries)
          {
          //some logic
           }

And execute the method:

updategrid(subquery1);
updategrid(subquery2);

When i try to use var in the method when defining it is not liking it. Please help me in how to do that. Thanks.

Answer 1

Use Object or dynamic

void updategrid(object queries)

void updategrid(dynamic queries)

var -> static type that is determined by the right side of expression. Cannot be used as parameter/return type

object -> Base class for all .NET types.

dynamic -> The type is resolved at runtime. Hence compile time checks are not made, and intellisense is not available. It has performance cost also.

Answer 2

void updategrid(var queries)

Is not valid C#.

var is syntactic sugar - the variable has a type, but you don't need to declare it if the compiler can statically determine what it should be.

With a parameter, the compiler doesn't have enough information to determine the type.

Similarly, you can't declare a variable with var without assignment:

var something;

---

You will need to ensure the types of subquery1, subquery2 and the parameter to updategrid are all the same.