PHP 关联数组 - 将逗号分隔值拆分为单独的数组行

Question

我有一个关联数组，“CAT”中的一些值有多个单词，用逗号分隔。

我想将它们拆分成单独的数组条目（每个逗号分隔的单词创建另一个数组条目），如下所示。

我知道我可以使用 explode() 用逗号分隔这些值，但不确定如何从中创建新的数组条目？

$categories = explode(',', $details[0]['CAT']);

当前数组结构：

Array
(
    [0] => Array
        (
            [ID] => 50829
            [CAT] => "furniture,home,garden"
        )

    [1] => Array
        (
            [ID] => 50832
            [CAT] => "kids"
        )

    [2] => Array
        (
            [ID] => 50854
            [CAT] => "toys"
        )
)

想要的结果：

Array
(
    [0] => Array
        (
            [ID] => 50829
            [CAT] => "furniture"
        )

    [1] => Array
        (
            [ID] => 50829
            [CAT] => "home"
        )

    [2] => Array
        (
            [ID] => 50829
            [CAT] => "garden"
        )

    [3] => Array
        (
            [ID] => 50832
            [CAT] => "kids"
        )

    [4] => Array
        (
            [ID] => 50854
            [CAT] => "toys"
        )
)

非常感谢您的帮助！

Answer 1

虽然您总是可以使用非常神秘的技巧，但通常很容易完全按照您描述的方式完成这项工作。您想要展开 CAT 索引并创建一个新数组，每个值都与原始索引相关联。所以，就这样做吧：

// Assume $old_array is your original array.
$new_array = array(); // Originally empty.
foreach($old_array as $e) { // For each element in the old array...
  $cats = explode(',',$e['CAT']);
  // $cats is every word exploded (one word if there is no comma).
  foreach($cats as $cat) { // For each word in $cats...
    $new_array[] = array('ID'=>$e['ID'], 'CAT'=>$cat);
    // Add a pair to the new array that has the ID and the cat word.
  }
}

完成后，$new_array 就是您要求的分解版本。

Answer 2

您可以简单地使用 foreach 重新创建一个新数组。对于“CSV 字符串”中的每个类别，您可以在输出数组中添加“ID”+“新 CAT”：

$array = [
    ['ID' => 50829, 'CAT' => 'furniture,home,garden'],
    ['ID' => 50832, 'CAT' => 'kids'],
    ['ID' => 50854, 'CAT' => 'toys'],
];

$out = [];                              // output array
foreach ($array as $item) {             // for each entry of the array
    $cats = explode(',', $item['CAT']); // split the categories
    foreach ($cats as $cat) {           // for each cat
        $out[] = [                      // create a new entry in output array
           'ID'  => $item['ID'],        // with same ID
           'CAT' => $cat,               // the "sub" category
        ];
    }
}

var_export(array_values($out));

array (
  0 => 
  array (
    'ID' => 50829,
    'CAT' => 'furniture',
  ),
  1 => 
  array (
    'ID' => 50829,
    'CAT' => 'home',
  ),
  2 => 
  array (
    'ID' => 50829,
    'CAT' => 'garden',
  ),
  3 => 
  array (
    'ID' => 50832,
    'CAT' => 'kids',
  ),
  4 => 
  array (
    'ID' => 50854,
    'CAT' => 'toys',
  ),
)

或者创建一个没有“CAT”的相同数组：

$out = [];
foreach ($array as $item) {
    $cats = explode(',', $item['CAT']);
    unset($item['CAT']);                  // unset the original "CAT"
    foreach ($cats as $cat) {
        $out[] = $item + ['CAT' => $cat]; // copy $item and add "CAT"
    }
}

PHP 关联数组 - 将逗号分隔值拆分为单独的数组行

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