在 useRef 中获取 .current 值

Question

I have a start/stop timer function that will start or stop the timer. It works perfectly but I'm trying to have it stop at 30 seconds and run saveTrial() . I've tried console logging timer.current and time at various locations, but neither are representing what the current timer is showing in seconds.

const [time, setTime] = useState(0);
let timer = useRef(0);

const startStopTimer = () => {
   if (!timer.current)
     timer.current = setInterval(() => {
         setTime(time => time + 1);
      }, 1000);
   } else {
     clearInterval(timer.current);
     timer.current = 0;
   }
};

Answer 1

Including time in useEffect as a dependency works perfectly.

useEffect(() => {
    if (time === 10) {
        saveTrial();
    };
}, [time]);