Return a custom class from function

I have a variable that is of type class. Within that class is a variable of another class type.

I need to change the values of the class within the class, and I thought I could do that by creating a function that can return the type class. But I can't seem to figure out how.

I know I could do this with a constructor, and pass in the values I need, but it would be so much nicer if you could create a function that returns the class instead.

Can you do this?

Thanks for your help,

EDIT : sorry, yea reading this back it doesn't really make a lot of sense.

so I have a couple of classes, with one of them holding the other class as a variable.

 public class bezier {
         public Vector3[] controlPoint;
         public float length;
         public boundingbox boundary; 
     }
 
     public class road {
         public int typeIndex;
         public int[] intersection;
         public bezier[] spline; 
     }

I then declare a new variable of type "road". I later need to change the information in spline. There's a lot of information in spline, and I was hoping I could do something like this :

 example.spline = SetSplines(some inputs...);

with SetSplines being a function, that returns the data type spline.

 Spline SetSplines (parameters){
 
         ....using the paramaters, add values to the spline class
        return theSplineInfo
 
 }

• didn't add what Id like to do in the function, its not really relevant*

Now you cant do this, because you cant make the type of the function some custom type. The work around would be to make it a void function, and have it save to some temporary variable of type spline, and then copy the contents of this temporary variable into example.spline . But that's really messy, and I was hoping there was a workaround. :) Thanks