Hint
Arrow callbacks inside methods inherit the method's this — solving the classic callback this-loss problem.
const timer = {
seconds: 0,
start() {
const tick = () => ++this.seconds;
tick(); tick(); tick();
return this.seconds;
}
};
console.log(timer.start());3
Explanation: Arrow function tick inherits this from start's context (timer). Each tick() increments timer.seconds.
Key Insight: Arrow callbacks inside methods inherit the method's this — solving the classic callback this-loss problem.