Uncaught SyntaxError：Setter必须只有一个形式参数 [英] Uncaught SyntaxError: Setter must have exactly one formal parameter

问题描述

我正在尝试理解JS上的getter和setter，我似乎无法传递此错误。任何人都可以提供任何有关我出错的原因吗？

I'm trying to understand getters and setters on JS and I can't seem to get pass this error. Can anyone provide any insight as to why I'm getting this error?

var book = {
    year: 2004,
    edition:1,
    get newYear(){
        return "Hello, it's " + this.year;
    },
    set newYear(y, e){
        this.year = y;
        this.edition = e;
    }
};

未捕获的SyntaxError：Setter必须只有一个形式参数

Uncaught SyntaxError: Setter must have exactly one formal parameter

推荐答案

当您指定setter表示的值时，将调用setter函数：

The setter function is called when you assign the value that setter represent:

var obj = {
  set a(newVal) { console.log("hello"); }
}
obj.a = 1; // will console log "hello"

正如你所看到的那样对于一个二传手机没有意义采用乘法参数，但它允许你在设置之前自由操纵值：

As you can see it doesn't make sense for a setter to take multiply arguments, but it gives you the freedom to manipulate the value before it is set:

var person = {
  surname: "John",
  lastname: "Doe",
  get fullname() {
    return this.surname + " " + this.lastname;
  },
  set fullname(fullname) {
    fullname = fullname.split(' ');
    this.surname = fullname[0];
    this.lastname = fullname[1];
  }
};

console.log(person.fullname); // "John Doe"
person.fullname = "Jane Roe";
console.log(person.surname); // "Jane"
console.log(person.lastname); // "Roe"

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