Do you know what will be the output of this code? const timer = { seconds: 10, start() { setTimeout(() => console.log(this.seconds)); }, }; timer.start();

Why does an arrow function in setTimeout keep this?

Do you know what will be the output of this code?

JavaScript

const timer = {
  seconds: 10,
  start() {
    setTimeout(() => console.log(this.seconds));
  },
};

timer.start();

Show answer and explanation

The answer is 10.

The arrow function has no this of its own, so it uses the one from start(), which is timer. A regular function callback would lose it.