PHP and JS implement a human-readable way to convert file size

function my_formatSize($size){
$size = doubleval($size);
$rank =0;
$rankchar ='Bytes';
while($size>1024){
 $size = $size/1024;
 $rank++;
}
if($rank==1){
 $rankchar="KB";
}
else if($rank==2){
 $rankchar= "MB";
}
else if($rank==3){
 $rankchar="GB";
}
$size = number_format($size, 2, '.', '');
return "" .$size." ".$rankchar;
}

2. js implementation code

function my_formatSize($size){
 var size = parseFloat($size);
 var rank =0;
 var rankchar ='Bytes';
 while(size>1024){
size = size/1024;
rank++;
 }
 if(rank==1){
rankchar="KB";
 }
 else if(rank==2){
rankchar="MB";
 }
 else if(rank==3){
rankchar="GB";
 }
 return size.toFixed(2)+ " "+ rankchar;
}
?>

Note: in the code Keep 2 decimal places.