如何在对象构造函数中添加数组属性？答案

【问题标题】：How to add an array property in an object constructor?如何在对象构造函数中添加数组属性？
【发布时间】：2021-04-26 12:50:26
【问题描述】：

const myCountry = function (country, capital, language, population) {

     (this.country = country),

     (this.capital = capital),

     (this.language = language),

     (this.population = population),
 
     (this.neighbours = []);
   
};

const Utopia = new myCountry("Utopia", "rabat", "arabic", "18 million", [
  "algeria",
  "tunisia",
]);

【问题讨论】：

在构造函数中添加optional neighbours parameter，例如function MyCountry(country, capital, language, population, neighbours = [])并使用this.neighbours = neighbours
谢谢！可以，忘记参数了

标签： javascript object constructor

【解决方案1】：

使用spread syntax

class myCountry {
  constructor(country, capital, language, population, neighbours) {
    this.country    = country
    this.capital    = capital
    this.language   = language
    this.population = population
    this.neighbours = [...neighbours]
  }
}

const Utopia = new myCountry('Utopia', 'rabat', 'arabic', '18 million', ['algeria','tunisia'])


console.log( Utopia.neighbours )

【讨论】：