PHP检查数组对象键值而不使用循环/foreach答案

【问题标题】：PHP check array object key value without using loop/foreachPHP检查数组对象键值而不使用循环/foreach
【发布时间】：2015-01-14 03:18:57
【问题描述】：

只是为了学习更多 PHP 技术，我在循环 foreach 中如此使用，我想找到一些其他方法来检查数组对象。假设我们有这样的结果：

 Array
(
    [0] =; stdClass Object
        (
            [gallery_id] => 38
            [artist_id] => 58
            [title] => Appearances
            [description] => Appearances
            [photo_file] => 
            [status] => 1
            [insert_timestamp] => 2014-08-07 03:27:23
            [update_timestamp] => 2014-08-07 15:26:24
            [url] => talents/58/photos/38/Appearances
            [position] => 
        )

    [1] => stdClass Object
        (
            [gallery_id] => 36
            [artist_id] => 58
            [title] => Endorsements
            [description] => Endorsements
            [photo_file] => 
            [status] => 1
            [insert_timestamp] => 2014-08-07 03:17:28
            [update_timestamp] => 2015-01-13 15:50:09
            [url] => talents/58/photos/36/Endorsements
            [position] => 1
        )

    [2] => stdClass Object
        (
            [gallery_id] => 34
            [artist_id] => 58
            [title] => Magazine Covers
            [description] => Magazine Covers
            [photo_file] => 
            [status] => 1
            [insert_timestamp] => 2014-08-07 02:54:27
            [update_timestamp] => 2015-01-13 15:50:10
            [url] => talents/58/photos/34/Magazine-Covers
            [position] =&gt; 2
        )
)

我知道我们可以这样做来检查对象中的值：

$myFlag = 2;

foreach($objArr as $obj){

  if($obj->position == $myFlag){

    return true;
  }

}

但是有没有办法在不使用循环的情况下检查它？一种更有效的方法，因为我觉得每当我使用它时（大部分时间），它不是那么有效，并且不知何故需要时间来处理。

【问题讨论】：

"请忽略 &gt as =>" --- 你为什么不想让它自己可读？
“效率不高，并且需要时间来处理” --- 如果您需要在数组中查找某些内容，则必须对其进行迭代。所以总是O(n)

标签： php arrays arrayobject

【解决方案1】：

如何使用带有闭包的array_filter。

$myFlag = 2;
$target = array_filter($objArr, function($elem) use($myFlag){
        return $elem->position === $myFlag;
    });

print_r($target);

结果是……

Array
(
    [2] => stdClass Object
        (
            [gallery_id] => 34
            [artist_id] => 58
            [title] => Magazine Covers
            [description] => Magazine Covers
            [photo_file] =>
            [status] => 1
            [insert_timestamp] => 2014-08-07 02:54:27
            [update_timestamp] => 2015-01-13 15:50:10
            [url] => talents/58/photos/34/magazine-covers
            [position] => 2
        )

)

【讨论】：