preg_match_all undefined偏移错误

Question

这里可能有一个正则表达式错误，但我无法解决它。

我得到“Undefined offset: 0”错误，无法获得标题的值。

这是我的代码。 INEEDTHISONE是我想要取得的头衔。

for ($j = 1; $j <= 1; $j++) { 
    for ($i = 0; $i < 5; $i++) { 
     $site = file_get_contents("http://example.com/index.php?route=product/category&path=395&page=$j");  
     preg_match_all('@<div class="name csstwo" title="INEEDTHISONE"><a itemprop="name" href="http://example.com/id/(.*?)/(.*?).html&amp;path=(.*?)">(.*?)</a></div>@', $site, $title);   
     $title[2][$i] = strip_tags($title[2][$i]); // strip tags 
     $title[2][$i] = preg_replace('~.*?>~', '', $title[2][$i]); // remove a tag and messy stuff 

     echo $title[2][$i]."<br>"; // gives undefined offset error. 

} 

详细错误。

line24 = $title[2][$i] = strip_tags($title[2][$i]);

line27 = echo $title[2][$i]."<br>";

Notice: Undefined offset: 0 in /Applications/MAMP/htdocs/test3.php on line 24 

Notice: Undefined offset: 1 in /Applications/MAMP/htdocs/test3.php on line 27 


Notice: Undefined offset: 1 in /Applications/MAMP/htdocs/test3.php on line 24 


Notice: Undefined offset: 2 in /Applications/MAMP/htdocs/test3.php on line 24 

Notice: Undefined offset: 1 in /Applications/MAMP/htdocs/test3.php on line 27 


Notice: Undefined offset: 3 in /Applications/MAMP/htdocs/test3.php on line 24 

Notice: Undefined offset: 1 in /Applications/MAMP/htdocs/test3.php on line 27 


Notice: Undefined offset: 4 in /Applications/MAMP/htdocs/test3.php on line 24 

Notice: Undefined offset: 1 in /Applications/MAMP/htdocs/test3.php on line 27 

Answer 1

我改变

preg_match_all('@<div class="name csstwo" title="INEEDTHISONE"><a itemprop="name" href="http://example.com/id/(.*?)/(.*?).html&amp;path=(.*?)">(.*?)</a></div>@', $site, $title);   

到

preg_match_all('@<div class="name csstwo" title="INEEDTHISONE"><a itemprop="name" href="http://example.com/id/(.*?)/(.*?).html&path=(.*?)">(.*?)</a></div>@', $site, $title); 

和问题就解决了。

& 

引起了问题。

Answer 2

尝试改变如下：

for ($j = 1; $j <= 1; $j++) { 
    for ($i = 0; $i < 5; $i++) { 
     $site = file_get_contents("http://example.com.com/index.php?route=product/category&path=395&page=$j");  
     preg_match_all('@<div class="name csstwo" title="INEEDTHISONE"><a itemprop="name" href="http://example.com/id/(.*?)/(.*?).html&amp;path=(.*?)">(.*?)</a></div>@', $site, $title); 
     if(isset($title[2][$i])){ 
      $title[2][$i] = strip_tags($title[2][$i]); // strip tags 
      $title[2][$i] = preg_replace('~.*?>~', '', $title[2][$i]); // remove a tag and messy stuff 

      echo $title[2][$i]."<br>"; // gives undefined offset error. 
     } 
}