Q:

Merging 2 JSON at specified positions using PHP

I have 2 JSON array from two mysql tables ie, db_events and db_ads.
Inside JSON values from db_events, I want to add first JSON value from db_ads at position 5 and second value at position 10 respectively.
How can I implement this. Is this is possible.
JSON from table db_events is,
{
  "events_from_category": [
    {
      "id": "1",
      "name": "Demo Event"
    },
    {
      "id": "2",
      "name": "Demo"
    },
    {
      "id": "3",
      "name": "Event"
    },
    {
      "id": "4",
      "name": "fgvnjhfrjht"
    },
    {
      "id": "5",
      "name": "fgvnjhfrjht"
    },
    {
      "id": "6",
      "name": "fgvnjhfrjht"
    },
    {
      "id": "7",
      "name": "fgvnjhfrjht"
    },
    {
      "id": "8",
      "name": "fgvnjhfrjht"
    },
   {
      "id": "9",
      "name": "fgvnjhfrjht"
   },
   {
      "id": "10",
      "name": "fgvnjhfrjht"
   }
  ]
}

JSON from table db_ads is,
{
  "ads": [
    {
      "id": "1",
      "ads_name": "ads 1"
    },
    {
      "id": "2",
      "ads_name": "ads 2"
    }
  ]
}

My resulting JSON should be,
{
  "ads": [
    {
      "id": "1",
      "name": "Demo Event"
    },
    {
      "id": "2",
      "name": "Demo"
    },
    {
       "id": "3",
       "name": "Event"
    },
    {
       "id": "4",
       "name": "fgvnjhfrjht"
    },
    {
       "id": "1",
       "ads_name": "ads 1"
    },
    {
       "id": "6",
       "name": "fgvnjhfrjht"
    },
    {
       "id": "7",
       "name": "fgvnjhfrjht"
    },
    {
       "id": "8",
       "name": "fgvnjhfrjht"
    },
    {
       "id": "9",
       "name": "fgvnjhfrjht"
    },
    {
       "id": "2",
       "ads_name": "ads 2"
    }
  ]
}

A:

The first thing to note is that json can be decoded in to an array using:
$aryRecords = json_decode($strRecords);
$aryAds = json_decode($strAds);

Then, because you are not just appending, it will be necessary to start looping through the array to insert the ads at certain points:
$aryTemp = array();
$intCount = 0;
/* Make sure pointer at the start of the ads array */
reset($aryAds);

/* Start looping through your results */
foreach($aryRecords as $aryCurrentRecord) {
    $intCount++;

    /* Check if counter divisible by 5 */
    if($intCount %5 != 0) {
        $aryTemp[] = current($aryAds);
        /* Move the pointer in the ads array forward */
        next($aryAds);
    }

    $aryTemp[] = $aryCurrentRecord;
}

/* Recreate your JSON object */
$strOutput = json_encode($aryTemp);

