Question

I know structs are value types but then I do not understand why this works:
EDIT: I mean, why this.Size.Height does not work then?

struct A
{
    int height;

    public int Height
    { 
        get
        {
            return height;
        }

        set
        {
            height = value;
        }
    }
}

//... class Main
{
    A a = A();
    a.Height = 5;  //works. Why? I thought it should say "cannot modify as it is not variable". I think the properties should return copy of this struct...?
}

Second question – I have read I do not need to use “new” with structs but it does not work without it for me.

Answer 1

“this.Size.Height = 5” does not work because when a value type is used as the type of a property, the above line of code would actually mean “this.get_Size().set_Height(5)”, and the result of the get_Size() call is a copy of the original, being a value type.

Thus, were it allowed by C#, setting the property value to 5 would change the copy’s value rather than the original property value, which is highly undesirable.

Of course, this does not apply when the value type property of a class is changed via a local variable, so this scenario can be safely be supported.