How can I return a variable at last call of recursive function?

Question

I have a recursive function. How can I return a value from this recursive function at the last call?

public function deneme($parent_id = 0, $sub_mark = 0, $str = '') {
    $this->db->select('*');
    $this->db->from('categories');
    $this->db->where('parent_id = ' . $parent_id);
    $this->db->order_by('id', 'ASC');
    $query = $this->db->get();
    if($query->num_rows() > 0) {
        $str .= '<ul>';
        foreach($query->result_array() as $row) {
            if ($parent_id == 0) {
                $str .= '<li class="active">';
            } else {
                $str .= '<li>';
            }
            $str .= '<a href="index.html">' . $row['name'] . '</a> </li> '; 
            $sub_mark++;
            $this->deneme($row['id'], $sub_mark, $str);
        }
        $str .= '</ul>';
    }
}

I want to return the str variable.

Nigel Ren · Accepted Answer · 2018-12-08T20:29:47.233

2

Looks as though you need a couple of changes, first to return the built up string from the routine at the end...

        }
        $str .= '</ul>';
    }
    return $str;
}

The second is where you call the routine recursively, you need to set the the return value to the string you are generating...

$str = $this->deneme($row['id'], $sub_mark, $str);

edited Dec 08 '18 at 20:29

answered Dec 08 '18 at 20:18

Nigel Ren

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It was going fine but it had go too much, to being limitless loop. I need to stop this at the very last :/ – Muhammed Çağlar TUFAN Dec 08 '18 at 20:27
I think I was adding the string to itself. I've changed the last line of the code to be `=` instead of `.=` (remove the dot). – Nigel Ren Dec 08 '18 at 20:30
How a monster you are!!! Are you crazy?? You do not know which data model do i use? What I want to do exactly! Also, you could be never faced with this problem forever! How can you see the problem in the code that easily? Thanks man, you are awesome! – Muhammed Çağlar TUFAN Dec 08 '18 at 21:11
You made me live 5 more years now, thanks up buddy! Seriously! – Muhammed Çağlar TUFAN Dec 08 '18 at 21:24

How can I return a variable at last call of recursive function?

1 Answers1