Question

retireingAge方法如何访问同一Person函数构造函数中的calculateAge方法的值？

var Person = function(name, job, yearOfBirth) {
  this.name = name;
  this.yearOfBirth = yearOfBirth;
  this.calculateAge = function() {
    console.log(2018 - this.yearOfBirth)
  };
  this.retirementAge = function(el) {
    console.log(66 - this.calculateAge)
  }
}

var john = new Person('John', 'teacher', 1998);
john.retirementAge(john.calculateAge());

Answer 1

如果要通过调用获取值，则需要从this.calculateAge返回一个值。完成此操作后，您只需调用函数this.calculateAge()，它便会按预期工作：

let Person = function(name, job, yearOfBirth) {
  this.name = name;
  this.yearOfBirth = yearOfBirth;
  this.calculateAge = function() {
    return 2018 - this.yearOfBirth
  };
  this.retirementAge = function(el) {
    return 66 - this.calculateAge()
  }
}

var john = new Person('John', 'teacher', 1998);
console.log("Age:", john.calculateAge())
console.log("Years to retirement:", john.retirementAge())

Answer 2

它可以访问它，您只需忘记括号并返回值即可。

var Person = function(name, job, yearOfBirth) {
  this.name = name
  this.yearOfBirth = yearOfBirth
  this.calculateAge = function() {
    return 2018 - this.yearOfBirth
  };
  this.retirementAge = function(el) {
    return 66 - this.calculateAge()
  }
}

var john = new Person('John', 'teacher', 1998);
console.log(john.retirementAge(john.calculateAge()))

从函数构造函数访问方法

2 个答案: