- substr: documentation ( source)
- preg_match: documentation ( source)
- round: documentation ( source)
<?php
$num = [2.117647058, 0.002117647058];
foreach($num as $n){
if(substr($n,0,1) > 0){
echo round($n, 2) . "\n";
}else{
preg_match("/([0\.]+)(\d{1,2})/", $n, $m);
echo $m[0] . "\n";
}
}