这是Nathan Smith 960网格的CSS中找到的clearfix：

/* http://www.yuiblog.com/blog/2010/09/27/clearfix-reloaded-overflowhidden-demystified */

.clearfix:before,.clearfix:after {
  content: '\0020';
  display: block;
  overflow: hidden;
  visibility: hidden;
  width: 0;
  height: 0;
}

.clearfix:after {
  clear: both;
}

/*
  The following zoom:1 rule is specifically for IE6 + IE7.
  Move to separate stylesheet if invalid CSS is a problem.
*/

.clearfix {
  zoom: 1;
}

这里是Paul Irish的HTML5 Boilerplate中的clearfix：

/* The Magnificent Clearfix: Updated to prevent margin-collapsing on child elements.
   j.mp/bestclearfix */

.clearfix:before,.clearfix:after {
    content: "\0020"; 
    display: block; 
    height: 0; 
    overflow: hidden;
}

.clearfix:after { clear: both; }

/* Fix clearfix: blueprintcss.lighthouseapp.com/projects/15318/tickets/5-extra-margin-padding-bottom-of-page */

.clearfix { zoom: 1; }

你可以看到他们非常相似.但是他们是不同的.

有人有任何洞察力吗？

哪个更好？为什么？