I have a struct lying in a class as below, which I think is not good. Structs should be in a separate file, however, in this case, this struct is only used in a class. What is the best practice for a C# struct?
class StudentMangement
{
private struct Student
{
public string Name { get; set; }
public int Age { get; set; }
public string Grade { get; set; }
}
}
There's not a lot to go on here, but consider this. Can someone's age be -10? Will a student ever be 1000 years old? An int can be both of these values. That means a simple default getter/setter isn't sufficient. You'll need to write some bounds checking in the setter and throw an exception if someone tries to set Student.Age to an unreasonable number.
Having a private struct or class is fine. However, Student should not be a struct. From MSDN:
AVOID defining a struct unless the type has all of the following characteristics:
- It logically represents a single value, similar to primitive types (
int,double, etc.).- It has an instance size under 16 bytes.
- It is immutable.
- It will not have to be boxed frequently.
Is Student immutable? No, it has public setters for Name, Age, and Grade. Mutable structs lead to confusing behaviour. To quote an answer on StackOverflow
Structs are value types which means they are copied when they are passed around.
So if you change a copy you are changing only that copy, not the original and not any other copies which might be around.
Does Student represent a single value, similar to primitive types? Again, no. Things that would match this criteria include coordinates, rectangles, colours, etc.
