解决php使用strip_tags()去除html标签后仍有空白的方法

$subject = strip_tags($newsRs['content']);//去除html标签
$pattern = '/\s/';//去除空白
$content = preg_replace($pattern, '', $subject);      
$seodata['articledescription'] = mb_substr($content, 0, 80);//截取80个汉字

<p>
  你好
</p>
<p>
  <br />
</p>
<p>
  alsdkjf;laskjd;flasj;
</p>
<p>
  asdjfasjd;lkafsj;lfdkj
</p>
<p>
  aksdjfl;ak
</p>

  你好
      空行...
  alsdkjf;laskjd;flasj;
      空行...
  asdjfasjd;lkafsj;lfdkj
      空行...
  aksdjfl;ak

你好alsdkjf;laskjd;flasj;asdjfasjd;lkafsj;lfdkjaksdjfl;ak