Stacking a variable in reverse in PHP

Question

I have a loop spitting out values and are put into a string:

$all_values = "";
while loop {
  $value = "...";
  $all_values .= $value . ",";
}

Output: 1,3,8,2,10...

What's the simplest way to output the same thing but numbers in reverse so the above example would come out like ...10,2,8,3,1

Answer 1

Put everything into an array and then join it together, reversed:

$all_values = array();
while loop {
  $value = "...";
  $all_values[] = $value;
}
$all_values = implode(',', array_reverse($all_values));

This is also more efficient if there are millions of values.

Answer 2

Add after your code:

$ar = explode(',', $all_values);
$revAr = array_reverse($ar);
$all_values = implode(',', $revAr);