php - PHP foreach 循环数组错误为“未定义变量”但值存在

Question

我在数组中有一个变量 $users 。倾倒它我有：

array(7) {
  [0]=>
  array(6) {
    ["'ev_id'"]=>
    string(1) "1"
    ["'user_email'"]=>
    string(17) "zoom@zoom.com"
    ["'status_role'"]=>
    string(1) "0"
    ["'registration'"]=>
    string(1) "0"
    ["'confirmation'"]=>
    string(1) "0"
    ["'participation'"]=>
    string(1) "1"
  }
  [1]=>
  array(6) {
    ["'ev_id'"]=>
    string(1) "1"
    ["'user_email'"]=>
    string(24) "miao@miao.com"
    ["'status_role'"]=>
    string(1) "0"
    ["'registration'"]=>
    string(1) "0"
    ["'confirmation'"]=>
    string(1) "0"
    ["'participation'"]=>
    string(1) "1"
  }
  [2]=>
  array(6) {
    ["'ev_id'"]=>
    string(1) "1"
    ["'user_email'"]=>
    string(20) "bau@bau.com"
    ["'status_role'"]=>
    string(1) "0"
    ["'registration'"]=>
    string(1) "0"
    ["'confirmation'"]=>
    string(1) "0"
    ["'participation'"]=>
    string(1) "1"
  }
}

这是我的代码：

echo "<pre>";var_dump($users);
foreach ($users as $key => $value) {
echo $value['ev_id'];
}

我变得疯狂，因为我想简单地循环并回显数组中的“ev_id”值，但我收到一个错误：

Notice:  Undefined index: ev_id

值“ev_id”存在，您可以在转储中看到。为什么我收到未定义的索引？