jquery - JS/JQuery : How to switch class several times in a loop way?

Question

如何循环多次切换一个item的class？我尝试了以下 1/3 成功的各种组合。第一次切换点击有效(news->part)，第二次点击无效(part->easy)，第三次无效(easy->news)。提前致谢。

HTML

<td class="news">Click on me!<td>
<td class="news">Click on me too!<td>

CSS

.news { border: 3px solid red ; }
.part { border: 3px solid orange ; }
.easy { border: 3px solid green ; }

JQUERY:

$("td").click(function () {
  if (        $("td").hasClass('news')) {
    $(this).removeClass("news").addClass('part');   /* click 1: works*/
  } else if ( $("td").hasClass('part')) {
    $(this).removeClass('part'  ).addClass('easy'); /* click 2: doesn't*/
  } else {
    $(this).removeClass('easy'  ).addClass('news'); /* click 2: doesn't*/
  }
});

Answer 1

Javascript

$("td").click(function () {
  if ($(this).hasClass('news')) {
    $(this).removeClass("news").addClass('part');   /* click 1: works*/
  } else if ( $(this).hasClass('part')) {
    $(this).removeClass('part'  ).addClass('easy'); /* click 2: doesn't*/
  } else {
    $(this).removeClass('easy'  ).addClass('news'); /* click 2: doesn't*/
  }
});

示例:http://jsfiddle.net/sRvcK/