Question

     $i = 0;
   $suggestion = 'page';
   $suggestions = array();
  while ($arg = arg($i++)) {
  $arg = str_replace(array("/", "\\", "\0"), '', $arg);
   $suggestions[] = $suggestion . '-' . $arg;
   if (!is_numeric($arg)) {
    $suggestion .= '-' . $arg;
   }
 }

i am a newbie of drupal,i can’t follow the above code well, hope someone can explain it to me.i know the first line is assign the 0 to $i,then assign ‘page’ to an array. and i know arg is an array in drupal.
for example, now the url is example.com/node/1. how to use this url to use the above code.

Answer 1

It looks like its purpose is to generate ID strings (probably for a CSS class) depending on paths and excludes numeric components of the path out of the generated ID.
For example, 'my/123/article' produces the ID "page-my-article".

It seems this comes from a function (because the loop reads parameters using arg()) and that it expects Drupal paths such as "node/123/edit".

So the function would be called something like that:

mystery_function("my/123/article", "even/better/article");

---

Variables:

$i is the variable that stores the loop index

$suggestion is a String that store the generated ID. It is initialized to “page” because the ID is meant to have the syntax “page-SOMETHING”.

$arg comes from the while loop: it reads the parameters passed to the mystery function one by one

$suggestions is an array that contains the generated IDs, one per argument passed to the mystery function.

---

In the loop:

The “$arg = str_replace...” line removes unwanted characters like “\” (however that line could definitely be improved).

The “$suggestions[] = ...” line adds the ID to the array of results.

The “if (!is_numeric($arg)...” line excludes numbers from the generated ID (e.g. “my/123/article” is probably supposed to produce “my-article”)

The “$suggestion .= ...” line appends the value of “$arg” to the value of “$suggestion” and stores it in “$suggestion”

---

But honestly, I wouldn’t advise to use that code: I doubt it works as intended given $suggestion isn’t reinitialized at each loop so the value of the first path will get attached to the second, and to the third, and so on, and I doubt that is intentional.