(PHP 5, PHP 7, PHP 8)
ArrayIterator::offsetUnset — Unset value for an offset
Unsets a value for an offset.
   If iteration is in progress, and ArrayIterator::offsetUnset() is used to
   unset the current index of iteration, the iteration position will be advanced to the next index.
   Since the iteration position is also advanced at the end of a
   foreach loop body, use of
   ArrayIterator::offsetUnset() inside a
   foreach loop may result in
   indices being skipped.
  
keyThe offset to unset.
没有返回值。
