Question

我一直致力于一个网页的功能，该网页应该显示来自JSON对象的信息，具体取决于两个属性，即出勤日和开始时间。 JSON和函数如下如下：

var courses = [{
  "dept": "CSC",
  "id": "3380",
  "instructor": "Douglas",
  "Location": "012 Lockett",
  "Start_Time": "8:00",
  "End_Time": "9:30",
  "Attendance": "Monday"
}, {
  "dept": "CSC",
  "id": "3380",
  "instructor": "Douglas",
  "Location": "012 Lockett",
  "Start_Time": "10:30",
  "End_Time": "11:30",
  "Attendance": "Monday"
}, {
  "dept": "CSC",
  "id": "3380",
  "instructor": "Douglas",
  "Location": "012 Lockett",
  "Start_Time": "12:30",
  "End_Time": "1:30",
  "Attendance": "Wednesday"
}];

function plotCourse() {
  var i;
  for (i = 0; i < courses.length; i++) {
    var course = courses[i];
    console.log(course);
    if (course.Attendance == "Monday" && course.Start_Time == "10:30") {
      alert(course.Attendance);
      alert(course.Start_Time);
    }
  }
}

我正在使用alert（）进行测试。但是，我似乎没有得到返回值，我有点难过，可能会发生什么。

提前致谢。

Answer 1

您忘了给它打电话：plotCourse();，或者使用 IIFE 。请检查一下

var courses = [{
  "dept": "CSC",
  "id": "3380",
  "instructor": "Douglas",
  "Location": "012 Lockett",
  "Start_Time": "8:00",
  "End_Time": "9:30",
  "Attendance": "Monday"
}, {
  "dept": "CSC",
  "id": "3380",
  "instructor": "Douglas",
  "Location": "012 Lockett",
  "Start_Time": "10:30",
  "End_Time": "11:30",
  "Attendance": "Monday"
}, {
  "dept": "CSC",
  "id": "3380",
  "instructor": "Douglas",
  "Location": "012 Lockett",
  "Start_Time": "12:30",
  "End_Time": "1:30",
  "Attendance": "Wednesday"
}];

(function() {
  var i;
  for (i = 0; i < courses.length; i++) {
    var course = courses[i];
    console.log(course);
    if (course.Attendance == "Monday" && course.Start_Time == "10:30") {
      alert(course.Attendance);
      alert(course.Start_Time);
    }
  }
})(); /* IIFE*/

Answer 2

希望你在调用这个函数。

在这里工作：

var courses = [{
  "dept": "CSC",
  "id": "3380",
  "instructor": "Douglas",
  "Location": "012 Lockett",
  "Start_Time": "8:00",
  "End_Time": "9:30",
  "Attendance": "Monday"
}, {
  "dept": "CSC",
  "id": "3380",
  "instructor": "Douglas",
  "Location": "012 Lockett",
  "Start_Time": "10:30",
  "End_Time": "11:30",
  "Attendance": "Monday"
}, {
  "dept": "CSC",
  "id": "3380",
  "instructor": "Douglas",
  "Location": "012 Lockett",
  "Start_Time": "12:30",
  "End_Time": "1:30",
  "Attendance": "Wednesday"
}];

function plotCourse() {
  var i;
  for (i = 0; i < courses.length; i++) {
    var course = courses[i];
    console.log(course);
    if (course.Attendance == "Monday" && course.Start_Time == "10:30") {
      console.log(course.Attendance);
      console.log(course.Start_Time);
    }
  }
}
plotCourse(); //Involed the function

Answer 3

您忘了拨打plotCourse()功能。

var courses = [{
  "dept": "CSC",
  "id": "3380",
  "instructor": "Douglas",
  "Location": "012 Lockett",
  "Start_Time": "8:00",
  "End_Time": "9:30",
  "Attendance": "Monday"
}, {
  "dept": "CSC",
  "id": "3380",
  "instructor": "Douglas",
  "Location": "012 Lockett",
  "Start_Time": "10:30",
  "End_Time": "11:30",
  "Attendance": "Monday"
}, {
  "dept": "CSC",
  "id": "3380",
  "instructor": "Douglas",
  "Location": "012 Lockett",
  "Start_Time": "12:30",
  "End_Time": "1:30",
  "Attendance": "Wednesday"
}];

function plotCourse() {
  var i;
  for (i = 0; i < courses.length; i++) {
    var course = courses[i];
    console.log(course);
    if (course.Attendance == "Monday" && course.Start_Time == "10:30") {
      alert(course.Attendance);
      alert(course.Start_Time);
    }
  }
}

plotCourse();

Answer 4

您提出的示例不是被调用的函数。 iniltre我对 FOR 循环进行了小修正.. =）

function plotCourse() {
  for (var i = 0; courses[i]; i++) { // Control if the element exists
    var course = courses[i];
    console.log(course);
    if (course.Attendance == "Monday" && course.Start_Time == "10:30") {
      alert(course.Attendance);
      alert(course.Start_Time);
    }
  }
}

plotCourse(); // launch the function!

Answer 5

正如其他人已经说过的那样，你需要调用这个函数。当我打电话给它时，它对我有用。

JSON / JavaScript函数问题

5 个答案: