Concept 001 :
ref
tells the compiler that the object is initialized before entering the function, while out
tells the compiler that the object will be initialized inside the function.
So while
ref
is two-ways, out
is out-only.
Concept 002 :
The
ref
modifier means that:- The value is already set and
- The method can read and modify it.
The
out
modifier means that:- The Value isn't set and can't be read by the method until it is set.
- The method must set it before returning.
For more detail click here.