While working on anElectron appPomolectron, I needed to handle different time intervals throughsetInterval() function of JavaScript.
I basically needed to implement three timers in my app:

• Pomodoro of 25 minutes
• Short break of 5 minutes
• Long break of 10 minutes

I could think of two ways to implement countdown timer for all three cases. One, to implement different timers by using three differentsetInterval(). Second, finding another way to utilize the samesetInterval() for all three timers.

Solution

So, I've tried my hands on the second approach. I can use the samesetInterval() for all three timers by assigning it to a variable like below,

varpomodoroIntervalId;functionstartTimer(duration,display){timer=duration;pomodoroIntervalId=setInterval(function(){if(--timer<0){timer=duration;}minutes=parseInt(timer/60,10);seconds=parseInt(timer%60,10);minutes=minutes<10?'0'+minutes:minutes;seconds=seconds<10?'0'+seconds:seconds;display.textContent=minutes+":"+seconds;if(minutes==0&&seconds==0){notifyUser();}},1000);}

And then utilize the samestartTimer() across other timers by first clearing the current time interval usingclearInterval() method passing the interval ID. In our case I've assigned it to a global variablepomodoroIntervalId. This basically clears the currently running time interval, so that it can be utilized next time another timer has been set. The code would look like below...

functionresetTimer(){clearInterval(pomodoroIntervalId);}

This gives us the benefit of using the samesetInterval() function across fidderent use cases which makes the code clean and sleek. And I think it's a really handy feature of JavasScript.