<?php
$data = '{"info":[{"id":1, "title":"original title", "name":"john doe", "timestamp":"0.5"}, {"id":2, "title":"another title", "name":"foo bar", "timestamp":"1"}]}';
 
$info = json_decode($data, true)['info'];
 
usort($info, function ($a, $b) {
    if ($a['timestamp']  == $b['timestamp']) {
        return 0;
    }
    return ($a['timestamp'] > $b['timestamp']) ? -1 : 1;
});
 
foreach ($info as $item) {
    echo "{$item['id']} {$item['title']}\n";
}

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