Question

I have a

 List<string>     

List<string> students; 
students.Add("123Rob"); 
students.Add("234Schulz"); 

and a

Dictionary<string,string> 

Dictionary<string, string> courses = new Dictionary<string, string>(); 
courses .Add("Rob", "Chemistry");   
courses .Add("Bob", "Math");  
courses .Add("Holly", "Physics"); 
courses .Add("Schulz", "Botany");

My objective now is to get a List with the values – {Chemistry,Botany} .

In other words, I am trying to get the LINQ equivalent of

select value from [courses]
where [courses].key in 
(
select [courses].key from courses,students where [students].id LIKE '%courses.key%'
)

How should the LINQ query be framed?

Answer 1

This is the correct answer:

var values = from c in courses
             where students.Any(s => s.IndexOf(c.Key, StringComparison.OrdinalIgnoreCase) >= 0)
             select c.Value;

Tested on my machine.
Hope this can help.