Question

我觉得奇怪的是，instructors_students函数与任何类都没有关联，也不是教师类的方法。如果可能的话，我想知道如何做到这一点。代码以它的方式工作，但它是以这种方式真正以对象为导向的。社区有什么意见？

function Person(person){
    this.title = person.title;
    this.firstname = person.firstname;
    this.lastname = person.lastname;
}

Person.prototype.fullName = function(){
    return this.title + " " + this.firstname + " " + this.lastname;
}

function Instructor(instructor){
    this.id = instructor.id;
    Person.call(this, instructor);
}

Instructor.prototype = new Person({});
Instructor.prototype.constructor = Instructor;

function Student(student){
    this.id = student.id;
    Person.call(this, student);
}

Student.prototype = new Person({});
Student.prototype.constructor = Student;    

function Tutorial(tutorial){
    this.id = tutorial.id;
    this.instructor = tutorial.instructor;
    this.day = tutorial.day;
    this.begin = tutorial.begin;
    this.finish = tutorial.finish;
}

function Register(register){
    this.id = register.id;
    this.year = register.year;
    this.week = register.week;
    this.tutorial = register.tutorial;
    this.students = register.students;
}

function instructors_students(instructor){
    students_taught = new Array();
    registers.forEach(function(register){
        if (register.tutorial.instructor == instructor){
            register.students.forEach(function(student){
                if (students_taught.indexOf(student) == -1){
                    students_taught.push(student);
                }
            });
        }
    });
    return students_taught;
}

function list_students(students){
    student_list = '';
    students.forEach(function(student){
        student_list += student.fullName() + ', ';
    });
    student_list.substring(0, student_list.length - 3);
    return student_list;
}

function display(text){
    var body = document.getElementsByTagName('body')[0]; 
    var div = document.createElement('div');
    var text = document.createTextNode(text);
    div.appendChild(text);
    body.appendChild(div);
}

// ** Load Data Here **

display('Instructor 1s Students: ' + list_students(instructors_students(instructors[1])));

Answer 1

我认为在原型上设置方法会更好，但我不明白为什么你改变这样的构造函数，你可以使用Object.create（或非标准的__proto__）< / p>

Answer 2

代码以它的方式工作，但它是否以这种方式真正以对象为导向。社区有什么意见？

是的，这将是更多的OOP。目前你的构造函数几乎什么都没做，而且只有一个共享方法。它可能是好的（甚至更清洁/更短）省略它们并且只是在普通数据上运行静态函数：

function fullName(person){
    return person.title + " " + person.firstname + " " + person.lastname;
}

function instructors_students(instructor) {
    var students_taught = [];
    registers.forEach(function(register) {
        if (register.tutorial.instructor == instructor)
            register.students.forEach(function(student) {
                if (students_taught.indexOf(student) == -1)
                    students_taught.push(student);
            });
    });
    return students_taught;
}

function list_students(students) {
    return students.map(fullName).join(', ');
}

function display(text) {
    var body = document.getElementsByTagName('body')[0]; 
    var div = document.createElement('div');
    div.appendChild(document.createTextNode(text));
    body.appendChild(div);
}

// ** Load Data Here **

display('Instructor 1s Students: ' + list_students(instructors_students(instructors[1])));

我想知道如果可能的话我会怎么做

当然有可能。该方法如下所示：

Instructor.prototype.getStudents = function() {
    var instructor = this,
        students_taught = [];
    registers.forEach(function(register) {
        if (register.tutorial.instructor == instructor)
            register.students.forEach(function(student) {
                if (students_taught.indexOf(student) == -1)
                    students_taught.push(student);
            });
    });
    return students_taught;
}

及其调用：

display('Instructor 1s Students: '+list_students(instructors[1].getStudents()));

是否应该将某些方法放在类之外

2 个答案: