在php中搜索數組？

Question

我有像頁面下面的數組。我想找到[itag] => 22的數組編號。 在這個例子中，這是[1]，是指：

[1] => Array 
     (
      [url] => asd2 
      [quality] => hd720 
      [fallback_host] => ax2 
      [type] => video/mp4; codecs=\"avc1.64001F, mp4a.40.2\" 
      [itag] => 22 
     ) 

如何能找到這在這些陣列結構：？

Array 
(
    [0] => Array 
     (
      [url] => asd1 
      [quality] => hd720 
      [fallback_host] => ax1 
      [type] => video/webm; codecs=\"vp8.0, vorbis\" 
      [itag] => 45 
     ) 

    [1] => Array 
     (
      [url] => asd2 
      [quality] => hd720 
      [fallback_host] => ax2 
      [type] => video/mp4; codecs=\"avc1.64001F, mp4a.40.2\" 
      [itag] => 22 
     ) 

    [2] => Array 
     (
      [url] => asd3 
      [quality] => large 
      [fallback_host] => ax3 
      [type] => video/webm; codecs=\"vp8.0, vorbis\" 
      [itag] => 44 
     ) 

    [3] => Array 
     (
      [url] => asd4 
      [quality] => large 
      [fallback_host] => ax4 
      [type] => video/x-flv 
      [itag] => 35 
     ) 



) 

Answer 1

和低技術含量的解決方案，沒有任何花哨：

$matchKey = null; 
foreach($array as $key => $item) { 
    if ($item['itag'] == 22) { 
     $matchKey = $key; 
     break; 
    } 
} 

if($matchKey === null) { 
    echo 'Not found.'; 
} 
else { 
    echo 'Key found: '.$matchKey; 
} 

Answer 2

array_filter：http://php.net/manual/en/function.array-filter.php

<?php 
$matches = array_filter($arr, function($el) { 
    return $el['itag'] == 22; 
}); 
print_r($matches); 
// or 
$key = key($matches); 
?> 

如果22是一個變量，你必須導入/使用它進入封閉的範圍：

... 
$matches = array_filter($arr, function($el) use ($someVar) { 
    return $el['itag'] == $someVar; 
...