Question

I would like to build an in-memory table data structure with 4 columns so I can look up values based on any combination of the columns (using linq for example).
Is there a built-in data type for this or do I have to craft one myself (obviously I can’t)?

Answer 1

Unless you have something specific in mind, I would declare a type with 4 properties with suitable names and types, i.e.

public class SomethingSuitable {
    public int Foo {get;set;}
    public string Bar {get;set;} 
    public DateTime Blap {get;set;}
    public float Blip {get;set;} 
}

and use any list/array/dictionary etc as necessary, or just

data.Single(x => x.Bar == "abc");

etc.