フリー問題

問題文

A reviewer asks what an array brings with it beyond its parts. Which answer holds?

選択肢

1. A field for the count of parts alone, because an array type stands apart from the root class and passes nothing down
2. A field for the count of parts that is open to read and settled once, a copying routine that hands back the same array type, and the members passed down from the root class apart from the copying one, because the list of members is drawn up that way
3. A field for the count of parts of an array that a program may write to, a copying routine that reports a checked failure, and the members passed down from the root class apart from the copying one, because the count of parts is kept in a place where a program is free to adjust it
4. A routine for the count of parts that is open to read, a copying routine that hands back the root class, and the members passed down from the root class with the copying one among them, because an array is laid out as an ordinary class whose shape the compiler writes out for it behind the scenes