Machine-translated by Google. Questions are authored in English.
Top

Discussion

Which one of the following statements about what a class must provide to be usable in a for-each loop is true?

  • A.It must implement Iterable, or the expression must be an array.
  • B.It must implement Iterator, supplying hasNext and next directly.
  • C.It must implement Collection, since for-each is defined over collections.
  • D.It must implement Comparable, so the loop knows the traversal order.

Answer: A

The enhanced for statement is defined over an array or an Iterable, whose single method returns an Iterator. Implementing Iterator itself is not enough and is a poor idea anyway, because such an object could only be traversed once.

No comment is present. Be the first to comment.
Loading…

Post your comment

Please log in or register to post a comment.