Php/docs/class.seekableiterator
(PHP 5 >= 5.1.0, PHP 7)
简介
The Seekable iterator.
接口摘要
SeekableIterator extends Iterator {
abstract public seek
( int $position
) : void
/* 继承的方法 */
abstract public Iterator::current ( ) : mixed
abstract public Iterator::key ( ) : scalar
abstract public Iterator::next ( ) : void
abstract public Iterator::rewind ( ) : void
abstract public Iterator::valid ( ) : bool
}
Example #1 Basic usage
This example demonstrates creating a custom SeekableIterator, seeking to a position and handling an invalid position.
<?phpclass MySeekableIterator implements SeekableIterator { private $position; private $array = array( "first element", "second element", "third element", "fourth element" ); /* Method required for SeekableIterator interface */ public function seek($position) { if (!isset($this->array[$position])) { throw new OutOfBoundsException("invalid seek position ($position)"); } $this->position = $position; } /* Methods required for Iterator interface */ public function rewind() { $this->position = 0; } public function current() { return $this->array[$this->position]; } public function key() { return $this->position; } public function next() { ++$this->position; } public function valid() { return isset($this->array[$this->position]); }}try { $it = new MySeekableIterator; echo $it->current(), "\n"; $it->seek(2); echo $it->current(), "\n"; $it->seek(1); echo $it->current(), "\n"; $it->seek(10); } catch (OutOfBoundsException $e) { echo $e->getMessage();}?>
以上例程的输出类似于：
first element third element second element invalid seek position (10)
Table of Contents
- SeekableIterator::seek — Seeks to a position
/* 方法 */