Convert comma separated string to array

function commaSplit($s =null, $n=- 1) {
        return preg_split( '/[\s,]+/',$s ,$n, PREG_SPLIT_NO_EMPTY);
}
   
 //usage  
 print_r( commaSplit('book, garden , , ,, carrot, food, ,' ));

 
 //result
 Array
(
    [0] => book
    [1] => garden
    [2] => carrot
    [3] => food
)