PHP公告：未定義抵消：1的陣列

Question

我得到這個PHP錯誤：

PHP Notice: Undefined offset: 1

preg_match('!select \'(.*)\' AS!s', $html, $matches); 
$count = $matches[1]; 
echo "[+] Count: $count\n"; 

for ($i = 0; $i <= $count; $i++) 
{ 
    if ($count == 1) 
    { 
     $num = "0,1"; 
    } 
    else 
    { 
     $num = "$i,1"; 
    } 
} 

Answer 1

我假設有在$matches[1]不匹配，因此偏移1是無效的！