Question

I have a large JSON file with more than 200 items. There are 5 groups data in it. each group has at least 30 items. I distinguish them using "p" tag, like "p":"1","p":"2","p":"3","p":"4","p":"5" in the json data. Now I want get 2 items from each group and total for 10 items with a random orders.

For an easy explanation, I set some simple data like below. “p”:”1″ have 4 items in its group, “p”:”2″ have 4 items in its group.

Now how to make get 2 items from "p":"1" and 2 items with "p":"2" with a random orders?

$json = <<<ETO
[
   {
      "a":"apple",
      "p":"1"
   },
   {
      "a":"orange",
      "p":"1"
   },
   {
      "a":"pear",
      "p":"1"
   },
   {
      "a":"banana",
      "p":"1"
   },
   {
      "a":"Chauli",
      "p":"2"
   },
   {
      "a":"Carrot",
      "p":"2"
   },
   {
      "a":"Lettuce",
      "p":"2"
   },
   {
      "a":"Potato",
      "p":"2"
   }
]
ETO;

$data = json_decode($json);
shuffle($data);// some shuffle like this is very ugly...
foreach($data as $row){                         
      $aoo = 1;
      $boo = 1;
      if($row->p==1){
          echo $row->p.': '.$row->a.'<br />';
          $aoo++;
          if($aoo==2){
            break;  
          }
      }
      if($row->p==2){
          echo $row->p.': '.$row->b.'<br />';
          $boo++;
          if($boo==2){
            break;  
          }
      }
}

I need get the result like:

orange ("p":"1") Carrot ("p":"2") pear ("p":"1") Lettuce ("p":"2")

Lettuce ("p":"2") banana ("p":"1") Apple ("p":"1") Chauli ("p":"2")

In one word, get 2 Vegetables and 2 Fruits combine for a mixed orders. Thanks.

Answer 1

$values = json_decode($json, true);

$grouped = array();
foreach ($values as $value) {
    $grouped[$value['p']][] = $value;
}

$chosen = array();
foreach ($grouped as $group) {
    $keys = array_rand($group, 2);
    $chosen = array_merge($chosen, array_intersect_key($group, array_flip($keys)));
}

shuffle($chosen);