试图在javascript中循环遍历JSON数据

Question

我正在使用PHP脚本将JSON数据发送到我的网站。我正在使用javascript尝试迭代我的json数据，以便我可以将信息存储在数组中。

line var length = emails.length给出了电子邮件是对象的错误

<script>
      var emails;
      $.get("scripts/getUsers.php", function(data) {
        for(element in data.email) {
          emails.push(element);
        };
      });
      var length = emails.length;
      alert(length);
      for(i = 0; i < length; i++) {
        $('<div/>', {
          'class':'col-md-3 col-xs-12 widget widget_tally_box',
          'html':'<p>Hello' + i + '</p>'
        }).appendTo("body");
      }
</script> 

这是PHP脚本

<?php

require_once '../includes/DBCredentials.php';

$response = array();

if($_SERVER['REQUEST_METHOD'] == 'GET') {
$db = new mysqli(DATABASE_HOST, DATABASE_USER, DATABASE_PASSWORD, DATABASE_NAME);
$statement = $db->query("SELECT email FROM user");
while($row = $statement->fetch_assoc()) {
  $email = $row['email'];
  $response['email'] = $email;
}
echo json_encode($response);
}

?>