递归合并索引

Question

我有一个类似索引的数组，我试图合并在一起。出于某种原因，我无法绕过它。

原始数组

$seperateArray = json_decode('[
{ "tier1": "Group1", "tier2": "Blue", "tier3": "Round", "tier4": "Harold" },
{ "tier1": "Group1", "tier2": "Blue", "tier3": "Round", "tier4": "Arthur" },
{ "tier1": "Group1", "tier2": "Blue", "tier3": "Round", "tier4": "Tom" },
{ "tier1": "Group2", "tier2": "Blue", "tier3": "Round", "tier4": "Beth" },
{ "tier1": "Group3", "tier2": "Blue", "tier3": "Round", "tier4": "Peter" }]', true);

将其变为：

{
    "Group1": {
        "Blue": {
            "Round": [
                "Harold",
                "Arthur",
                "Tom"
            ]
        }
    },
    "Group2": {
        "Blue": {
            "Round": [
                "Peter"
            ]
        }
    }
}

这是我目前所处的位置，但我不知道我是否朝着正确的方向前进。

$newCombined = array();

//this each statement will show every tier 1-4 array object
foreach($seperateArray as $s) {

    if(!array_key_exists($s['tier1'], $newCombined) $newCombined[$s['tier1']] = array();
    if(!array_key_exists($newCombined[$s['tier1']][$s['tier2']], $newCombined[$s['tier1']])) $newCombined[$s['tier1']][$s['tier2']] = array();
    //.. and so on

}

Answer 1

如果只有select L.MemberNo, A.FirstName FROM Booking.Loans as L INNER JOIN Article.Items as I on L.ISBN = I.ISBN INNER JOIN Article.TitleAuthors as TA on I.TitleID = TA.TitleID INNER JOIN Article.Authors as A on TA.AuthorID = A.AuthorID 可以产生一个数组，那么循环和分配就很简单了（如果您对沉默通知没问题）：

tier4

使作业变得不那么神秘：

$array = json_decode('...', true);
$new = [];

foreach ($array as $e)
    @$new[$e['tier1']][$e['tier2']][$e['tier3']][] = $e['tier4'];

echo json_encode($new, JSON_PRETTY_PRINT); # to print what you asked for

从foreach ($array as $e) { list($t1, $t2, $t3, $t4) = array_values($e); @$new[$t1][$t2][$t3][] = $t4; } 返回到原始数组：

$new

Answer 2

Sidyll的回答很完美，但在我自己的解决方案上，我也会发布它：

$input = json_decode('[
  { "tier1": "Group1", "tier2": "Blue", "tier3": "Round", "tier4": "Harold" },
  { "tier1": "Group1", "tier2": "Blue", "tier3": "Round", "tier4": "Arthur" },
  { "tier1": "Group1", "tier2": "Blue", "tier3": "Round", "tier4": "Tom" },
  { "tier1": "Group2", "tier2": "Blue", "tier3": "Round", "tier4": "Beth" },
  { "tier1": "Group3", "tier2": "Blue", "tier3": "Round", "tier4": "Peter" }]', true);

$output = [];

foreach($input as $row) {
  $recursion = &$output;
  foreach($row as $key => $value) {
    if ($key != 'tier4' && !isset($recursion[$value])) {
      $recursion[$value] = [];
    }
    if ($key == 'tier4') {
      $recursion[] = $value;
    } else {
      $recursion = &$recursion[$value];
    }
  }
}

var_dump($output);

  

array（3）{[＆＃34; Group1＆＃34;] =＆gt; array（1）{[＆＃34; Blue＆＃34;] =＆gt; array（1）{[＆＃34; Round＆＃34;] =＆gt; array（3）{[0] =＆gt;字符串（6）＆＃34;哈罗德＆＃34; [1] =＆GT; string（6）＆＃34; Arthur＆＃34; [2] =＆GT; string（3）＆＃34; Tom＆＃34; }＆＃34; Group2＆＃34;] =＆gt; array（1）{[＆＃34; Blue＆＃34;] =＆gt; array（1）{[＆＃34; Round＆＃34;] =＆gt; array（1）{[0] =＆gt; string（4）＆＃34; Beth＆＃34; }＆＃34; Group3＆＃34;] =＆gt; array（1）{[＆＃34; Blue＆＃34;] =＆gt; array（1）{[＆＃34; Round＆＃34;] =＆gt; ＆amp; array（1）{[0] =＆gt;字符串（5）＆＃34;彼得＆＃34; }}}

不是特别自豪，但它确实有效。