Question

I have this php code:

$lines = file("data.csv");
$nested = array();
$links = array();

// first, create a structure that contains the connections between elements
foreach ($lines as $line) {
  list($child, $parent) = explode(",", $line);
  if (trim($child) == trim($parent)) {
    $nested[$parent] = null;
  } else {
    // add it to the children of parent
    $links[$parent][] = $child;
  }
}

function process(&$arr) {
  global $links;
  foreach ($arr as $key => $value) {
    // no more children => stop recursion
    if (!array_key_exists($key, $links)) {
      $array[$key] = null;
      continue;
    }
    // insert its children
    $arr[$key] = array_flip($links[$key]);
    // recurse down
    process($arr[$key]);
  }
}


function print_html($multi_dimensional_array)
{
    $m = $multi_dimensional_array;
    $keys = array();

    foreach($m as $key=>$value) {
            $keys[] = $key;
    }

    $i = 0;

    while($i < count($multi_dimensional_array)) {
        echo '<li><a href="#">'.$keys[$i].'</a>';
        if(is_array($multi_dimensional_array[$keys[$i]])) {
                echo '<ul>';
                print_html($multi_dimensional_array[$keys[$i]]);
                echo '</ul>';
        }
        echo '</li>';
        $i++;
    }
}

process($nested);

print_html($nested);

The data.csv format is (value,parent), an example would be:

one,one
two,two
three,three
sub_one,one
sub_one2,one
sub_two,two
sub_two2,two
sub_two3,two
sub_three,three
sub_sub_one,sub_one
sub_sub_one2,sub_one

Basically this what this PHP code does is create a multidimensional array that contains the parent name as key and the childs as values, and if a child also contains sub childs then it would be a key which contains subkeys, etc… and it will then print an html formatted list for that array.

How could I use C# to do what this php code does?

Answer 1

Arrays in C# aren’t like arrays in PHP. You’ll probably need to implement the Composite pattern to get the desired data structure. That’s just a pointer to the right (I think) direction for a small part of your task. If you do end up using the pattern, consider Dictionary<string, TComposite> for the type of children collection.