How to sort a JSON array with PHP

Question

First of all i'm a complete newbie to this, i have searched for solutions but none seem to do the trick.

So I am trying to sort this JSON array by date but i don't really know i should tackle this, any tips in the right direction are much appreciated!

["info":[
{"id":1, "title":"original title", "name":"john doe", "date":"2010-05-15"}, 
{"id":2, "title":"another title", "name":"foo bar", "date":"2009-04-11"},
...

So i'm getting the data like this

$data=file_get_contents('jsondata...');
$d=json_decode($data,true);

I would like to sort the data by date, any ideas how i should approach this? Is it also possible to return the year value only? So the output would be 2009 instead of 2009-04-11?

Thanks in advance

Answer 1

You can use usort and a custom comparison function:

$data = '{"info":[{"id":1, "title":"original title", "name":"john doe", "date":"2010-05-15"}, {"id":2, "title":"another title", "name":"foo bar", "date":"2009-04-11"}]}';

$info = json_decode($data, true)['info'];

usort($info, function ($a, $b) {
    return $a['date'] <=> $b['date'];
});

<=> works on strings here because a string comparison is also a date comparison when your dates are formatted as YYYY-MM-DD.

Then, to show the year value for an entry, you can parse the date into a DateTime and reformat it:

$date = DateTime::createFromFormat('Y-m-d', $item['date']);
$year = $date->format('Y');

Here's a demo.