prime number using for loop in php

php using prime number program
for($i=2;$i<50;$i++){
$counter=0;
for($j=2;$j<$i;$j++){
if($i%$j==0){
$counter++;
break;
}
}
// you can check instead if($i==$j)
if($counter==0){
echo $i.",";
}
}