If Iterator::valid() returns false, the foreach() loop will be terminated.
(PHP 5 >= 5.0.0, PHP 7)
Iterator::valid — Checks if current position is valid
This method is called after Iterator::rewind() and Iterator::next() to check if the current position is valid.
이 함수는 인수가 없습니다.
The return value will be casted to boolean and then evaluated.
성공 시 TRUE
를, 실패 시 FALSE
를 반환합니다.
If Iterator::valid() returns false, the foreach() loop will be terminated.
If your class implements also ArrayAccess interface, you could use as valid() body
function valid(){
return $this->offsetExists($this->position);
}