- print_r: documentation ( source)
- krsort: documentation ( source)
<?php
$array = array(
"2018-10" => 239,
"2018-11" => 264,
"2018-12" => 237,
"2019-01" => 211,
"2019-04" => "0",
"2019-03" => "0",
"2019-02" => "0"
);
krsort($array);
print_r($array);