show more implementation jquery

1var $li = $('ul li');
2var $shPets = $('.shPets');
3
4$shPets.each(function() {
5  var petType = $(this).data('pet');
6  $('ul li[data-pet=' + petType + ']')
7    .not('.shPets') //not shPets
8    .not(':first') //everything except first
9    .hide();
10});
11
12$('.shPets').click(function() {
13  var petType = $(this).data('pet');
14  if ($(this).text() == 'Show More..') {
15    $(this).text('Hide');
16    $('ul li[data-pet=' + petType + ']').show();
17  } else {
18    $(this).text('Show More..');
19    $('ul li[data-pet=' + petType + ']')
20      .not('.shPets') //not shPets
21      .not(':first') //everything except first
22      .hide();
23  }
24});