javascript - 增加计数器并动态更改依赖它的变量

Question

我怎样才能递增一个计数器并期望递增的计数器在使用它的对象值内发生变化？

想象一下:

var pizzaOrder = {
    id: "pizza",
    counter: 0,
    sentence: this.id + this.counter // first problem is here  
    // as I am getting NaN
};

pizzaOrder.counter++;

console.log(pizzaOrder.sentence);

预期输出:

"pizza1";

Answer 1

你不能像那样引用一个尚未完成创建的对象，但听起来你想在这里使用一个 getter:

var pizzaOrder = {
  id: "pizza",
  counter: 0,
  get sentence() {
    return this.id + this.counter;
  }
};
pizzaOrder.counter++;

console.log(pizzaOrder.sentence);