访问器：setter 不起作用

Question

I am playing with Javascript accessor properties (I am restarting from zero to study javascript), trying to create getter and setter for a simple object, here the code:

var dummy = {
        name: 'empty',
        description: 'static description',

        get nameAccessor(){return 'name value is: ' + this.name;},
        set nameAccessor(value){ this.name = value;},

        get descAccessor(){return 'desccription value is: ' + this.description;},
};

console.log(dummy.nameAccessor);
console.log(dummy.nameAccessor('Mazinga'));
console.log(dummy.nameAccessor);

But it throws an error:

Uncaught TypeError: Property 'nameAccessor' of object # is not a function

when it executes the setter code:

    console.log(dummy.nameAccessor('Mazinga'));

What's going wrong here?

EDIT :

Ok, it seems to be not a well-known feature of javascript, butI followed this example from Javascript: Definitive Guide

var o = { 
          data_prop: value,
          get accessor_prop() { /* function body here */ },
          set accessor_prop(value) { /* function body here */ }
    };

Answer 1

An accessor is not a function as a property of the object ("method"), but a function that is called when that property is assigned (set) or retrieved (get) . Use

dummy.nameAccessor = 'Mazinga';

to invoke the setter function.

In contrast, dummy.nameAccessor('Mazinga') gets the property "nameAccessor" (which results in the name string) and then tries to call it as a function, which will fail. It would work if your getter returned a function, but that is not what you want here.

Answer 2

dummy.nameAccessor不是一个函数，它是一个字符串name value is: empty 。

Answer 3

Your methods syntax is not correct, try :

var dummy = {

    name: 'empty',
    description: 'static description',

    getName : function(){return 'name value is: ' + this.name;},
    setName : function(value){ this.name = value;},
    getDesc : function(){return 'description value is: ' + this.description;}

};