遍历 javascript 中 class 的所有对象

Question

我有一个 class Student 和一个方法 eligibleForPlacements 检查是否学生有资格获得展示位置。如何遍历所有对象并使用该方法检查学生是否符合条件？

我创建了一个数组 static allObj = new Array(); 来存储所有对象，但它不起作用：

class Student {
  static noOfStudents = 0;
  static allObj = new Array();
  constructor(name1, age, phoneNumber, boardMarks) {
    this.name = name1,
      this.age = age,
      this.phoneNumber = phoneNumber,
      this.boardMarks = boardMarks
    Student.noOfStudents += 1;
    Student.allObj.push(this);
  }
  eligibleForPlacements(minMark) {
    return (age1) => {
      if (age1 < this.age && this.boardMarks > minMark) {
        console.log(`${this.name} is eligible for placements`);
      } else {
        console.log(`${this.name} is not eligible for placements`);
      }
    }
  }
}

//created two object and iterating through it

const lili = new Student('Lili', 16, '2827384788', 50);
const ria = new Student('Ria', 23, '2827384788', 30);

for (let i = 0; i < Student.allObj.length; i++) {
  Student[i].eligibleForPlacements(10)(5);
}

Answer 1

你错过了最后.allObj

class Student {
  static noOfStudents = 0;
  static allObj = new Array();
  constructor(name1, age, phoneNumber, boardMarks) {
    this.name = name1,
      this.age = age,
      this.phoneNumber = phoneNumber,
      this.boardMarks = boardMarks
    Student.noOfStudents += 1;
    Student.allObj.push(this);
  }
  eligibleForPlacements(minMark) {
    return (age1) => {
      if (age1 < this.age && this.boardMarks > minMark) {
        console.log(`${this.name} is eligible for placements`);
      } else {
        console.log(`${this.name} is not eligible for placements`);
      }
    }
  }
}

const lili = new Student('Lili', 16, '2827384788', 50);
const ria = new Student('Ria', 23, '2827384788', 30);

for (let i = 0; i < Student.allObj.length; i++) {
  // add .allObj here
  Student.allObj[i].eligibleForPlacements(10)(5);
}

Answer 2

您正在尝试读取 Student class 本身的索引，而不是 allObj 属性；将 Student[i].eligibleForPlacements(10)(5); 更改为 Student.allObj[i].eligibleForPlacements(10)(5); 并且工作正常：

class Student {
  static noOfStudents = 0;
  static allObj = new Array();
  constructor(name1, age, phoneNumber, boardMarks) {
    this.name = name1,
      this.age = age,
      this.phoneNumber = phoneNumber,
      this.boardMarks = boardMarks
    Student.noOfStudents += 1;
    Student.allObj.push(this);
  }
  eligibleForPlacements(minMark) {
    return (age1) => {
      if (age1 < this.age && this.boardMarks > minMark) {
        console.log(`${this.name} is eligible for placements`);
      } else {
        console.log(`${this.name} is not eligible for placements`);
      }
    }
  }
}

const lili = new Student('Lili', 16, '2827384788', 50);
const ria = new Student('Ria', 23, '2827384788', 30);

for (let i = 0; i < Student.allObj.length; i++) {
  Student.allObj[i].eligibleForPlacements(10)(5);
}

遍历 javascript 中 class 的所有对象

Loop through all the objects of a class in javascript

javascript

jquery

class