ArrayIterator::offsetUnset

(PHP 5, PHP 7, PHP 8)

ArrayIterator::offsetUnset — Unset value for an offset

说明

public ArrayIterator::offsetUnset(mixed $key): void

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.

参数

key: The offset to unset.

返回值

没有返回值。

参见

ArrayIterator::offsetGet() - Get value for an offset
ArrayIterator::offsetSet() - Set value for an offset

add a note

User Contributed Notes 3 notes

down

rkos... ¶

8 years ago


This is my solution for problem with offsetUnset
<?php

$a = new ArrayObject( range( 0,9 ) );
$b = new ArrayIterator( $a );

for ( $b->rewind(); $b->valid();  )
{
    echo "#{$b->key()} - {$b->current()} - <br>\r\n";
    if($b->key()==0 || $b->key()==1){
        $b->offsetUnset( $b->key() );
    }else {
        $b->next();
    }
}

var_dump($b);
?>

down

olav at fwt dot no ¶

10 years ago


When unsetting elements as you go it will not remove the second index of the Array being worked on. Im not sure exactly why but there is some speculations that when calling unsetOffset(); it resets the pointer aswell.

<?php

$a = new ArrayObject( range( 0,9 ) );
$b = new ArrayIterator( $a );

for ( $b->rewind(); $b->valid(); $b->next() )
{
    echo "#{$b->key()} - {$b->current()} - \r\n";
    $b->offsetUnset( $b->key() );
}

?>

To avoid this bug you can call offsetUnset in the for loop

<?php
/*** ... ***/
for ( $b->rewind(); $b->valid(); $b->offsetUnset( $b->key() ) )
{
/*** ... ***/
?>

Or unset it directly in the ArrayObject
<?php
/*** ... ***/
    $a->offsetUnset( $b->key() );
/*** ... ***/
?>

which will produce correct results

down

Adil Baig @ AIdezigns ¶

10 years ago


Make sure you use this function to unset a value. You can't access this iterator's values as an array. Ex:


<?php

$iterator = new \RecursiveIteratorIterator(new \RecursiveArrayIterator($arr));


foreach($iterator as $key => $value)

{

    unset($iterator[$key]); 

}

?>



Will return :


PHP Fatal error:  Cannot use object of type RecursiveIteratorIterator as array


offsetUnset works properly even when removing items from nested arrays.

add a note

官方地址：https://www.php.net/manual/en/arrayiterator.offsetunset.php

有任何技术问题请点击这里网站运营推广招聘

IT PHP 编程语言 Linux 开发编程科技 Elasticsearch HTML/CSS/XML 网络 JAVA NoSQL 数据库面试 C/C++ Golang Git 算法操作系统正则表达式 Redis 互联网 MySql JavaScript 运维软件国际架构设计 Mac OS TCP/IP Excel Vim Windows Socket Oracle VR MongoDB Python 运营 MemCache 商业硬件电子娱乐设计 nginx 摄影游戏 WordPress HTTP 团建数码电器

php7 安装fileinfo扩展 preg_split — 通过一个正则表达式分隔字符串 php位值,解决 PHP 中 usort 在值相同时改变原始位置的问题 [PHP] inet_pton/inet_ntop IP地址转换函数 array_multisort() 多字段排序 PHPMailer设置utf8 PHPMailer字符集CharSet ADORecordSet对象 [鸟哥]PHP_INT_MIN 和 -9223372036854775808 PHP 8.1 adodb手册 opcache预加载 Composer的Packagist资源 mysql面试题 php扩展开发支持php7的性能采集扩展 PHP7 mcrypt替代方案 PHP mkdir()写出来的权限与mode值不符合 php上周一、本周一、下周一日期 php设置cookie为httponly防止xss攻击 PHP json解析（json_decode）页面工具

略微加速

PHP官方手册 - 互联网笔记

ArrayIterator::offsetUnset

说明

参数

返回值

参见

User Contributed Notes 3 notes