如何从组中检索一段json数据？

Question

I have a peice of json data that contains a group of images and i want to retrieve the primary image. How do i grab it? The beginning hash for each item is generated.

{
   "c79638bdcd7e5e9f5cceffffc0dd0e73":{
      "filename":"c79638bdcd7e5e9f5cceffffc0dd0e73.jpg",
      "alt":"",
      "caption":"",
      "primary":true
   },
   "4eb0808fcf339f935a610d950e1726b2":{
      "filename":"4eb0808fcf339f935a610d950e1726b2.png",
      "alt":"",
      "caption":""
   },
   "34ec15fd06233c5e3271b0dc2565d04e":{
      "filename":"34ec15fd06233c5e3271b0dc2565d04e.png",
      "alt":"",
      "caption":""
   }
}

Answer 1

Just gonna make your text a string for these purposes. adapt as necessary.

$text  = '
{
   "c79638bdcd7e5e9f5cceffffc0dd0e73":{
      "filename":"c79638bdcd7e5e9f5cceffffc0dd0e73.jpg",
      "alt":"",
      "caption":"",
      "primary":true
   },
   "4eb0808fcf339f935a610d950e1726b2":{
      "filename":"4eb0808fcf339f935a610d950e1726b2.png",
      "alt":"",
      "caption":""
   },
   "34ec15fd06233c5e3271b0dc2565d04e":{
      "filename":"34ec15fd06233c5e3271b0dc2565d04e.png",
      "alt":"",
      "caption":""
   }
}';


$woo = json_decode($text,true);
$image = '';
foreach($woo as $k => $v)
{
  if(isset($v['primary'] && $v['primary']))
  {
    $image = $v['filename'];
  }

}