php parsing json using value from list - php

Question

I have a json like this:
"achievementsProgress": [
{
"value": 11,
"globalID": 23000000
},
{
"value": 11,
"globalID": 23000001
},
{
"value": 11,
"globalID": 23000002
},
{
"value": 147,
"globalID": 23000003
},
{
"value": 147,
"globalID": 23000004
},
{
"value": 147,
"globalID": 23000005
},
.....
]
It goes on like that and I need to be able to read the "value" field of every 3rd.
So globalID 23000002, 23000005, 23000008, 230000011 etc. All the way up to and including 65. And then I need to save those as variable names like:
$achievement1 for globalID 23000002
$achievement2 for globalID 23000005
etc.
Now I assume this has to be done in a loop.
So far I have this much.
$jsondata = file_get_contents($url);
$data = json_decode($jsondata, true)
and it would be
$data['achievementsProgress'] to get to the list of the above json.
How would I go about doing this?

Answer 1

Here is one way to do it. I think any way you'll be able to do this will need to involve variable variables.
$x = 1; // start a counter for your variable names
for ($i=2; $i < 65; $i+=3) { // start at index 2 (3rd value) and increment by 3
if (isset($data['achievementsProgress'][$i])) { // just in case there aren't actually 65
// Use variable variables to create the $achievement variables you want
${"achievement$x"} = $data['achievementsProgress'][$i]['value'];
}
$x++;
}
This example uses complex string syntax to create the variable variable.

Answer 2

Better do it like this:
$jsondata = file_get_contents($url);
$data = json_decode($jsondata, true);
$items=$data->achievementsProgress;
$result=[];
$i=1;
foreach($items as $item)
if($i++%3==0)
$result[$item->globalID]=$item->value;
//now $result contains map of data you wanted globalid => value
Now you can access it like this:
$result['23000000'] == 11 and so on