PHP pass and receive two dimensional array from form

Question

I am trying to pass two paired variables, a category and its id for multiple user-created categories from a webform to a file for processing. I want to keep them linked so

Answer 1

good and single syntax for creating two dimensional array;

  <input type="text" name="cat[]" value="cat1">
  <input type="text" name="cat[]" value="cat2">
    ...

While receiving cats;

echo $_POST['cat'][0] // echoes cat1
echo $_POST['cat'][1] // echoes cat2

Further example;

According to this definition,

<input type="text" name="cat[$cat][$id]" value="cat1">

foreach ($_POST['cat'] as $a=>$b){
    // $a == $cat
    foreach($b as $c=>$d) {
       // $c == $id
    }
}