利用php中strip_tags()去除html标签仍有空白的解决方法

$subject = strip_tags($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>
  张志斌张志斌张志斌张志斌张志斌张志
</p>
<p>
  <br />
</p>
<p>
  alsdkjf;laskjd;flasj;
</p>
<p>
  asdjfasjd;lkafsj;lfdkj
</p>
<p>
  aksdjfl;ak
</p>

  张志斌张志斌张志斌张志斌张志斌张志
  
  
  
  
  alsdkjf;laskjd;flasj;
  
  
  asdjfasjd;lkafsj;lfdkj
  
  
  aksdjfl;ak

张志斌张志斌张志斌张志斌张志斌张志alsdkjf;laskjd;flasj;asdjfasjd;lkafsj;lfdkjaksdjfl;ak