フリー問題

問題文

Three constructors of one class each open with an explicit call to another of them, and the build reports a cycle among the three. What is the standing rule, and what supports it?

選択肢

1. The language bars a constructor from opening with a call to another of them, because the body of a constructor opens with a call of the direct superclass when the author leaves it out, and any call that names the same class is turned down there
2. The language bars a constructor from reaching itself through those calls, because it is an error for a constructor to invoke itself through a series of one or more explicit calls that name the same class, and every step of the chain counts toward that series
3. The language bars a constructor from reaching itself through those calls, because it is an error for a constructor to invoke itself through a series of one or more explicit calls that name the same class, and only a chain of three or more is caught
4. The language bars a constructor from opening with a call to another of them, because the body of a constructor opens with a call of the direct superclass when the author leaves it out, and each explicit call replaces that one