php正则加亮关键字函数方法

function highlight_words($str, $words, $color = '#FFFF00') { 
if(is_array($words)) { 
   foreach($words as $k => $word) { 
     $pattern[$k] = "/\b($word)\b/is"; 
     $replace[$k] = '\\1'; 
   } 
} 
else { 
   $pattern = "/\b($words)\b/is"; 
   $replace = '\\1'; 
} 
  
return preg_replace($pattern,$replace,$str); 
}