Question

Given an array that gets populated with strings. I need following behavior:

foo = []
foo = add_search_string(foo, 'a')

foo should equal [‘a’]

foo = add_search_string(foo, 'a')

foo should equal [‘a’] because ‘a’ was already a search string

foo = add_search_string(foo, 'ab')

foo should equal [‘ab’] because ‘a’ is a substring of ‘ab’ and therefore can be removed

foo = add_search_string(foo, 'a')

foo should equal [‘ab’] because of the same reason as above

foo = add_search_string(foo, 'c')

foo should equal [‘ab’, ‘c’]

My function looks like this:

function add_search_string(search_strings, new_search_string) {
    var keep = true;
    var new_search_strings = []
    $.each(search_strings, function(i, search_string) {
        if (new_search_string == search_string) {
            keep = false;
        } else if (search_string.indexOf(new_search_string) >= 0) {
            keep = false;
        }
    });

    if (keep) {
        $.each(search_strings, function(i, search_string) {
            if (new_search_string.indexOf(search_string) == -1) {
                new_search_strings.push(search_string);
            }
        });
        new_search_strings.push(new_search_string);
        search_strings = new_search_strings;
    }
    return search_strings;
}

Is there a ‘better’ way to do this?

Answer 1

If the intention is to keep updating the same array I’d probably do something like this:

function add_search_string(search_strings, new_search_string) {
   var replaced = false;
   for (var i = search_strings.length -1; i >= 0; i--) {
      if (search_strings[i].indexOf(new_search_string) != -1) {
          // string found, so just return
          return search_strings;
      }
      if (new_search_string.indexOf(search_strings[i]) != -1){
          // existing string is a substring of new search string
          // if it already matched another element just remove the current one
          // otherwise replace the current one
          if (replaced)
              search_strings.splice(i,1);
          else
              search_strings[i] = new_search_string;
          replaced = true;
      }
   }
   // if not found add it
   if (!replaced)
      search_strings.push(new_search_string);
   return search_strings;
}

Although this function returns the array, it also updates the array you pass in so you don’t have to assign it back when you call the function, you can just say:

add_search_string(foo, 'a');