合并键在同一数组中匹配的关联数组值

Question

I am generating an associative array that I want to use to generate a JSON object but have a problem of duplicate keys with different values. I want the where the keys are duplicate, the values of are merged. I have checked online but all the solutions reference 2 different arrays not the same array.

The JSON Object is:

{
  "trailervideos": [
    {
      "category": "Video Games",
      "videos": {
        "description": "Trailer of the game Dark Souls II",
        "title": "Dark Souls 2 Announcement Trailer"
      }
    },
    {
      "category": "Video Games",
      "videos": {
        "description": "Trailer of the DLC Scholar of the First Sin for the game Dark Souls II",
        "title": "Dark Souls II Scholar of the First Sin - Forlorn Hope Trailer"
      }
    },
    {
      "category": "Video Games",
      "videos": {
        "description": "Trailer of the DLC Ashes of Ariendel for the game Dark Souls III",
        "title": "Dark Souls III Ashes of Ariandel - Announcement Trailer PS4"
      }
    },
    {
      "category": "Entertainment",
      "videos": {
        "description": "",
        "title": "intro"
      }
    }
  ]
}

What I want to achieve is all the values of repeated key "Video Games" combined so that I can generate a JSON object like:

{"trailervideos":[{"category":"Video Games","videos":[{"description":"Trailer of the game Dark Souls II","title":"Dark Souls 2 Announcement Trailer"},{"description":"Trailer of the DLC Scholar of the First Sin for the game Dark Souls II","title":"Dark Souls II Scholar of the First Sin - Forlorn Hope Trailer"},{"description":"Trailer of the DLC Ashes of Ariendel for the game Dark Souls III","title":"Dark Souls III Ashes of Ariandel - Announcement Trailer PS4"}],{"category":"Entertainment","videos":{"description":"","title":"intro"}}]}

Answer 1

There is no 'JSON-object'. JSON is a string reprentation a J avas S cript O bject N otation you can build a PHP object-array-structure from, using json_decode . To get a JSON string from PHP variables, the function json_encode is used.

The easiest way is to iterate over the trailervideos building a new associative array since there can only be unique keys. We can eleminate the key names by the function array_values later to prevent json_encode from building an object instead of an array because associative arrays do not exist in JavaScript.

This version does process all categories, "Video Games" as well as "Entertainment" and, if available, even more.

$a = [];

foreach (($o = json_decode($json))->trailervideos as $v)
{
  isset($a[$v->category]) || $a[$v->category] = new stdClass();
  $a[$v->category]->category = $v->category;
  $a[$v->category]->videos[] = $v->videos;
}

$o->trailervideos = array_values($a);

var_dump(json_encode($o));

The (formatted) JSON result looks like that:

{
  "trailervideos": [
    {
      "category": "Video Games",
      "videos": [
        {
          "description": "Trailer of the game Dark Souls II",
          "title": "Dark Souls 2 Announcement Trailer"
        },
        {
          "description": "Trailer of the DLC Scholar of the First Sin for the game Dark Souls II",
          "title": "Dark Souls II Scholar of the First Sin - Forlorn Hope Trailer"
        },
        {
          "description": "Trailer of the DLC Ashes of Ariendel for the game Dark Souls III",
          "title": "Dark Souls III Ashes of Ariandel - Announcement Trailer PS4"
        }
      ]
    },
    {
      "category": "Entertainment",
      "videos": [
        {
          "description": "",
          "title": "intro"
        }
      ]
    }
  ]
}