Question

In jQuery, filter() reduces your result to those elements that fulfill a certain condition.

This splits the list in two parts. Working with the “good half” of the elements is easy:

$("some selector").filter(function() {
  // determine result...
  return result;
}).each( /* do something */ );

But how can I work with the “other half” of my elements, too – but without doing the equivalent of this:

$("some selector").filter(function() {
  // determine result...
  return !result;
}).each( /* do something else */ );

Basically, I’d like to feed two separate /* do something */ parts to a single filter. One for those that match, and one for the others – without having to filter twice. Am I missing a jQuery function that does this?

---

P.S.: I guess I could do:

$("some selector").each(function() {
  // determine result...
  if (result)
    /* do something */
  else
    /* do something else */
});

But I was hoping for something nicer.

Answer 1

The method recommended by Kobi in plugin form:

$.fn.invert = function() {
  return this.end().not(this);
};

$('.foo').filter(':visible').hide().invert().show();

Note that invert() will not add a new element to the jQuery stack but replace the last one:

$('.foo').filter(':visible').invert().end(); // this will yield $('.foo'), not $('.foo:visible')

Edit: changed prevObject to end() at Tomalak’s suggestion.