Using Dependency Injection with Generic class

Question

I am using sitecore 9.3 and was trying to add configuration for dependency injection of the implemented repository as below:

<register
    serviceType="projectname.IRepository[[projectname.models.model1, projectname]],projectname" 
    implementationType="projectname.Repositories.Repository[[projectname.Models.model1, projectname]],projectname" />

But this doesn't work except after adding "`1" to the interface and the repository names as below:

<register
    serviceType="projectname.IRepository`1[[projectname.models.model1, projectname]],projectname"
    implementationType="projectname.Repositories.Repository`1[[projectname.Models.model1, projectname]],projectname" />

I want to know what this character "`1" represent, any one can advise?

Answer 1

"`1" is not Sitecore specific. It's how generic type names in .net can be encoded.

The number after "`" character (arity) stands for the number of generic parameters

E.g. "List`1[string]" means that it's a generic List type with 1 parameter of type string.

and "Dictionary`2[string, int]" stands for a generic Dictionary with 2 parameters where first one is a string and second one is an int.

You can read more in ECMA-335: "II.9 Generics" chapter