Explode a string in php excluding the ', ' within braces

Question

I have a string of this-

$str = "field1.id as field1, 
       DATE_SUB(field2, INTERVAL (DAYOFMONTH(field2)-1) DAY) as field2,   
       field3.name as field3";

Need to explode this into array with , as this:

$requiredArray = array(
  0 => field1.id as field1,
  1 => DATE_SUB(field2, INTERVAL (DAYOFMONTH(field2)-1) DAY) as field2
  2 => field3.name as field3
);

I've tried with explode but it doesn't works:

$requiredArray = explode(', ', $str); 
// doesn't work as "DATE_SUB(field2, INTERVAL ..." also gets exploded

Any trick/ideas?

Ebersole

You'll need to use a preg_split that can test if your comma is inside braces and only split if it isn't. Or perhaps something like preg_match_all('#\(.*?\)|[^,]+#', $str, $matches); var_dump($matches[0]); – Shah

you need regular expression. – Sincere

Nice clue, Thanks, I'll give it a try. +1 – Ebersole

@MarkBaker That doesn't work for now :(. – Ebersole

The principle of using a regexp should still apply, it's just getting the right regexp that is a problem; I'll see what I can find – Shah

This was not as obvious as I thought. Can anyone please help me out here ? Not working after several attempts :( – Ebersole

Maybe just use explode("\n", $str)? By line break, not by comma. – Janise

That is not a line break its a space, I've wrapped it just to make the question clear to display – Ebersole

take a look at: https://3v4l.org/OVHQh – Sincere

@FrayneKonok Yeah, I've checked this while googling it over, unfortunately this regex doesn't work in my case, may be need to modify it a little – Ebersole

I also surprised about it, But taking time to solve it. – Sincere

Answer 1

Please try this

$str = "field1.id as field1, 
       DATE_SUB(field2, INTERVAL (DAYOFMONTH(field2)-1) DAY) as field2,   
       field3.name as field3";

$buffer = '';
$stack = array();
$depth = 0;
$len = strlen($str);
for ($i=0; $i<$len; $i++) {
    $char = $str[$i];
    switch ($char) {
    case '(':
        $depth++;
        break;
    case ',':
        if (!$depth) {
            if ($buffer !== '') {
                $stack[] = $buffer;
                $buffer = '';
            }
            continue 2;
        }
        break;
    case ' ':
        if (!$depth) {
             $buffer .= ' ';
            continue 2;
        }
        break;
    case ')':
        if ($depth) {
            $depth--;
        } else {
            $stack[] = $buffer.$char;
            $buffer = '';
            continue 2;
        }
        break;
    }
    $buffer .= $char;
}
if ($buffer !== '') {
    $stack[] = $buffer;
}
echo "<pre>";
print_r($stack);
echo "</pre>";

Lordling

Yeah, I don't think regex can do this now. Although its a bigger soln, I'll go with it. Thanks! – Ebersole

#4538586 works well too :) – Ebersole

Answer 2

Try this :

preg_match_all('~(.*)[^(],?~', $str, $matches);

Skiba