javascript - 如何访问ajax返回的结果数组？

Question

嗯!!我的工作完美无缺，现在我又开始用头敲击键盘了。

我想访问数组内定义的列，但我未定义，但如果我使用下面代码片段中详细介绍的警报显示结果，我会看到以下内容:

[{"firstname":" Mr","0":" Mr","lastname":" Two","1":" Two","user_public_info_id":"3","2":"3","st_usage_id":null,"3":null},{"firstname":" Mr","0":" Mr","lastname":" Three","1":" Three","user_public_info_id":"5","2":"5","st_usage_id":null,"3":null}] 
*** 
g 
*** 
e 
*** 
undefined

这是 Ajax 代码:

$.ajax({
 type: "POST",
 url: "models/ajaxHandler.php",
 data: "handler=getStActivitySharingList&stu_id="+stu_id,
 datatype: "json",
 success: function(result){
    var count = 0;
    if (result !== null)
    {
       //display results
       alert(result + " <br />*** <br />" + result[0] +" <br />*** <br />" + result[1] + " <br />*** <br />"  + result[0]["firstname"]);

       //clears choice list
       clearOptions();

       //result = $.parseJSON(result); //if this is used cannot display result again
       alert (result);   

       $.each(result, function (i, elem) {
           alert("elem"+elem.st_usage_id );    //displays as undefined and won't break
           if (elem.st_usage_id === null)
           {
               count++;
               alert(elem.firstname + " "+ elem.lastname + " " + elem.user_public_info_id);
               appendOption(elem);
           }
       });              
     }
     alert(count);
     if (count === 0){
         noResultsAvailableOption();
     }else{
        resultsAvailableOption();
      }

        ShowDialog(false);
        e.preventDefault();
      },
      error: function(){
           alert("ajax failure: could not retrieve a list of contacts");
      }
  });

Answer 1

我不知道你如何从 PHP 返回它，但在 jquery 中尝试:

sucess: function (result)
{
    console.log(JSON.parse(result)); // parse string to json
}

参见json.org