ArrayIterator
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ArrayIterator::seek

(PHP 5 >= 5.0.0)

ArrayIterator::seek — Seek to position

说明

public void ArrayIterator::seek ( int $position )
Warning

本函数还未编写文档，仅有参数列表。

参数

position

The position to seek to.

返回值

没有返回值。

ArrayIterator
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PHP手册
PHP手册 - N: Seek to position

用户评论:

php at mattjanssen dot com (12-May-2011 04:53)

If you call ->seek() on a position that doesn't exist, you'll get the following error:
PHP Fatal error:  Uncaught exception 'OutOfBoundsException' with message 'Seek position 10 is out of range' in script.php:1

jon at ngsthings dot com (22-Oct-2008 01:08)

<?php
// didn't see any code demos...here's one from an app I'm working on

$array = array('1' => 'one',
               '2' => 'two',
               '3' => 'three');

$arrayobject = new ArrayObject($array);
$iterator = $arrayobject->getIterator();

if($iterator->valid()){
    $iterator->seek(1);            // expected: two, output: two
    echo $iterator->current();    // two
}

?>

adar at darkpoetry dot de (27-Mar-2007 07:54)

Nice way to get previous and next keys:

<?php

class myIterator extends ArrayIterator{

    private $previousKey;

    public function __construct( $array ) {
        parent::__construct( $array );
        $this->previousKey = NULL;
    }

    public function getPreviousKey() {
        return $this->previousKey;
    }

    public function next() {
        $this->previousKey = $this->key();
        parent::next();
    }

    public function getNextKey() {
        $key = $this->current()-1;
        parent::next();
        if ( $this->valid() ) {
            $return = $this->key();
        } else {
            $return = NULL;
        }
        $this->seek( $key );

        return $return;
    }
}

class myArrayObject extends ArrayObject {

    private $array;

    public function __construct( $array ) {
        parent::__construct( $array );
        $this->array = $array;
    }

    public function getIterator() {
        return new myIterator( $this->array );
    }

}
?>

And for testing:

<?php

$array['a'] = '1';
$array['b'] = '2';
$array['c'] = '3';

$arrayObject = new myArrayObject( $array );

for ( $i = $arrayObject->getIterator() ; $i->valid() ; $i->next() ) {
    print "iterating...\n";
    print "prev: ".$i->getPreviousKey()."\n";
    print "current: ".$i->key()."\n";
    print "next: ".$i->getNextKey()."\n";
}

?>

Output will be:

iterating...
prev:
current: a
next: b
iterating...
prev: a
current: b
next: c
iterating...
prev: b
current: c
next: