learning_jquery/Chapter 3/03.js

$(document).ready(function () {
  'use strict';

  $('#switcher h3').hover(function() {
    $(this).addClass('hover');
  }, function() {
    $(this).removeClass('hover');
  });
});

$(document).ready(function () {
  'use strict';

  $('#switcher').click(function (event) {
    $('#switcher button').toggleClass('hidden');
  });
});

$(document).ready(function () {
  'use strict';

  $('#switcher-default').addClass('selected');

  $('#switcher').click(function (event) {
    if ($(event.target).is('button')) {
      var bodyClass = event.target.id.split('-')[1];

      $('body').removeClass().addClass(bodyClass);

      $('#switcher button').removeClass('selected');
      $(event.target).addClass('selected');
      event.stopPropagation();
    }
  });
});