javascript - 如何访问多维 JSON 数据？

Question

我正在尝试访问 JSON 文件的某些字段的值。

console.log(objects.assignments.header.report_type);

我想打印HOMEWORK

<小时/>

Javascript

$.ajax({

      url:  "/BIM/rest/report/assignment",
      type: "POST",
      dataType : "json",
      data: {
        assessmentId: "206a9246-ce83-412b-b8ad-6b3e28be44e3",
        classroomId:  "722bfadb-9774-4d59-9a47-89ac9a7a8f9a"
      },

      success: function( objects ) {

        console.log( objects.assignments.header.report_type );

        // Result : Uncaught TypeError: Cannot read property 'report_type' of undefined

<小时/>

JSON 数据 - 我从 AJAX 调用中返回

{
  "assignments": [
    {
      "assignmentId": "SUMMARY",
      "name": "Summary",
      "header": {
        "section_num": "9.4",
        "report_type": "HOMEWORK",
        "problem_set": "Summary",
        "start_time": null,
        "student_am": 0,
        "student_total": 5,
        "due_time": null,
        "submit_am": 0,
        "submit_total": 0,
        "avg_score": "0.0",
        "danger": 0,
        "danger_list": "",
        "warning": 0,
        "warning_list": "",
        "success": 0,
        "success_list": ""
      }
    }
  ]
}

<小时/>

如何正确访问这些数据？

任何提示/帮助对我来说都意义重大。

提前致谢。

Answer 1

assignments 是一个数组，因此您需要访问特定元素。

console.log(objects.assignments[0].header.report_type);
                               ^^^