JSON/JavaScript関数の問題

Question

JSONオブジェクトからの情報を表示するWebページの機能について、出席者の日と開始時刻の2つの属性に応じて作業しています。次のようにJSONと機能があり、次のとおりです。

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); 
 
    } 
 
    } 
 
}

私はテスト目的のためにアラートを（）を使用しています。しかし、私は返された価値を得るようには思われません、そして、私はちょっと困惑して、何が起こっているかもしれません。

ありがとうございます。

Answer 1

あなたはこの関数を呼び出していたと思います。

ここで働い：

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 2

をあなたはそれを呼び出すことを忘れ：plotCourse();、またはその代わり生命維持を使用しています。この1

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 3

あなたが提案した例では、呼び出された関数ではなかった確認してください。 iniltreは、私は他の人がすでに述べたように

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 4

は、関数を呼び出す必要がある）= .. FORループに小さな修正を行いました。私がそれを呼んだとき、それは私のために働いています。

Answer 5

plotCourse()機能を呼び出すことを忘れました。

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();