Get JSON value which change everytime using php

I have a JSON file

{
  "status": "ok",
  "data": {
    "files": {
      "4d7cc5ec-2aef-48ec-9ebf-f811d4c77a5d": {
        "mimetype": "video/mp4",
        "link": "https://example.com/video.mp4",
        "name": "video.mp4",
        "size": 348353594
      }
    },
    "uploadTime": 1618074643,
    "totalSize": 348353594
  }
}

Now the value 4d7cc5ec-2aef-48ec-9ebf-f811d4c77a5d keeps changing every time the page is loaded. And I want to grab the value of link

My code is

//This one also not working. Gives 500 Internal Error.
$jsonfile = 'this is JSON file';
$json = json_decode($jsonfile);
$link = $json->data->files->4d7cc5ec-2aef-48ec-9ebf-f811d4c77a5d->link;
echo $link;

But the problem is 4d7cc5ec-2aef-48ec-9ebf-f811d4c77a5d keeps changing every time. How do I then get the value of link using PHP?

Answer

Use array_column() as well as true as a second parameter to json_decode()

$json = json_decode($jsonfile,true);
$link = array_column($json['data']['files'],'link');
var_dump($link[0]);

sample output: https://3v4l.org/oSQvo

Note: In case files contains multiple dynamic values then $link will give you array of all links. you can apply foreach() to iterate and get individual links