How to remove hyperlink in php

$str=preg_replace("/<a[^>]*href=[^>]*>|<\/[^a]*a[^>]*>/i","",$content);

ereg_replace("<a [^>]*>|<\/a>","",$content);

$find="this string is my find"; 
$string=&#39;<font color="red">这段内容将要被替换掉</font>&#39;;//将超链接替换成的内容 
echo ereg_replace(&#39;<a([^>]*)>([^<]*&#39;.$find.&#39;[^>]*)</a>&#39;,&#39;<font color="red">\\2</font>&#39;,$content);

//方法一 
preg_match_all(&#39;/<(a|a)[s]{0,1}[w=":()]*>[nrn]*(check user)[nrn]*</(a|a)>/i&#39;,$string,$matches); 
  
//方法二 
preg_match_all(&#39;/<a[dd]*>check user</a>/i&#39;,$string,$matches); 
print_r($matches); 
  
//方法三 
preg_match_all(&#39;/<a[^>]*>[^<]*</a>/i&#39;,$string,$matches); 
print_r($matches); 
  
//方法四 
preg_match_all(&#39;/<a.+?>check user</a>/is&#39;,$str,$arr); 
print_r($arr);