从 ajax 响应中提取数据


Extracting data from a ajax response

我需要从 php 数据中提取 URL,我该如何实现?

.PHP

$query = 'SELECT * FROM picture LIMIT 3';
$result = mysql_query($query);

while ($rec = mysql_fetch_array($result,  MYSQL_ASSOC)) {
    $url.=$rec['pic_location'].";";
}
echo json_encode($url);

阿贾克斯

 <script type="text/javascript">
    $(document).ready(function() {
    $(".goButton").click(function() {
       var dir =  $(this).attr("id");
   var imId = $(".theImage").attr("id");
   $.ajax({
      url: "viewnew.php",
      data: {
         current_image: imId,
         direction    : dir
      },
     success: function(ret){
          console.log(ret);
          var arr = ret;
          alert("first: " + arr[0] + ", second: " + arr[1]);
          alert(arr[0]);
          $(".theImage").attr("src", +arr[0]);
          if ('prev' == dir) {
        imId ++;
     } else {
        imId --;
     }
     $("#theImage").attr("id", imId);
          }
       });
    });
    });
    </script>

警报消息不起作用,它只是打印 H T(我认为这些是 http://...

您返回的字符串未解析为 JSON。只需将dataType: "json"添加到 ajax 设置中即可。

由于你在javascript中将其作为数组读取,因此您应该像这样返回它:

while ($rec = mysql_fetch_array($result,  MYSQL_ASSOC)) {
    $url[] = $rec['pic_location'];
}

你在PHP中发送一个字符串,并期望一个数组作为javascript中的响应。将 PHP 更改为

while ($rec = mysql_fetch_array($result,  MYSQL_ASSOC)) {
    $url[] = $rec['pic_location'];
}

和 JavaScript 到

$.ajax({
      url: "viewnew.php",
      dataType: "JSON",
      data: {
         current_image: imId,
         direction    : dir
      },
      success: function(ret){
          console.log(ret[0]);
          var arr = ret;
          alert(arr);  
          alert("first: " + arr[0] + ", second: " + arr[1]);    // THIS IS NOT WORKING!!!!
          if ('prev' == dir) {
            imId ++;
         } else {
            imId --;
         }
         $("#theImage").attr("id", imId);
      }
   });