PHP - 组合具有相同键值的数组

Question

我有一个包含多个对象的 JSON 数组，这是一个示例：

$people = [{"name":"John", "color":"green"}, 
           {"name":"Mary", "color":"green"}, 
           {"name":"Bob", "color":"red"}]

我使用json_decode($people, true) 将它们转换为数组...

现在假设我想合并具有相同color 的那些。我必须做array_merge_recursive($people[0], $people[1])，因为他们都有green 作为color。请注意，我必须指定要递归合并的那些。

$people 解码为数组格式后如何循环并自动递归合并具有相同键值的那些？

类似这样的：

foreach($people as $person) {
    // If a person has same color of previous
    // person then merge them recursively.
}

这样我就可以在循环后得到这个：

[{"name":"John, Mary", "color":"green, green"}, 
 {"name":"Bob", "color":"red"}]

Answer 1

使结果数组成为以颜色为键的关联数组。

$people_by_color = array();
foreach ($people as $person) {
    if (isset($people_by_color[$person['color']])) {
        $people_by_color[$person['color']]['name'] .= ', ' . $person['name'];
        $people_by_color[$person['color']]['color'] .= ', ' . $person['color'];
    } else {
        $people_by_color[$person['color']] = $person;
    }
}
$people_by_color = array_values($people_by_color); // Turn into indexed array