CODEWITHSUNDEEP
javascriptloopssetinterval
SADmiral
SADmiral

Reputation: 41

Stopping more than one setInterval in same Function (NodeJs)

I'm attempting to cancel multiple timers - here's my code :

timer1 = setInterval(func1,3000)

stopper=999
count=5
function func1(){
    console.log("called func1 ")
    if(count<=0){           //Count check, if zero , stop looping
        clearInterval(timer1)
        clearInterval(timer2)
    }else{                  //if count bigger than 0
        timer2 = setInterval(func2,3000)
        function func2(){
            count=count-1
            console.log("Called Func2 " + stopper)
            stopper=count 
        }
    }
}

When stopper hits 0, it stops writing "Called Func1", but it's still writing "Called Func2" over and over even if stopper is -999 - how do I stop looping this double setInterval?

Upvotes: 2

Views: 61

Answers (2)

dRoyson
dRoyson

Reputation: 1507

The reason this happens is every time func1 is called a new setInterval is being added to the stack.

One possible solution to this would be to replace setInterval for timer2 with setTimeout.

timer1 = setInterval(func1,3000)

stopper=999
count=5
function func1(){
    console.log("called func1 ")
    if(count<=0){           //Count check, if zero , stop looping
         clearInterval(timer1)
         clearTimeout(timer2)
    }else{                  //if count bigger than 0
         timer2 = setTimeout(func2,3000)
         function func2(){
             count=count-1
             console.log("Called Func2 " + stopper)
             stopper=count 
        }
    }
}

The second solution would be to clear the timer2 before setting a new one.

timer1 = setInterval(func1,3000)

stopper=999
count=5
function func1(){
    console.log("called func1 ")
    if(count<=0){           //Count check, if zero , stop looping
         clearInterval(timer1)
         clearInterval(timer2)
    }else{                  //if count bigger than 0
         timer2 = setInterval(func2,3000)
         function func2(){
             count=count-1
             console.log("Called Func2 " + stopper)
             stopper=count 
             clearInterval(timer2)
        }
    }
}

Hope this helps :)

Upvotes: 1

Fullstack Guy
Fullstack Guy

Reputation: 16908

The reason is that the timer2 is being overwritten every time by a new id of the setInterval call when the setInterval(func2,3000) is called from func1.

You are setting up a setInterval for func1 in the beginning it schedules several setInterval calls for the func2 in the else block. The func1 is being invoked 5 times and a separate setInterval for the func2 is setup for each func1 call.

Now there are multiple intervals set-up for func2 with multiple ids and each time this happens the timer2 is overwritten with the latest value of the id.

So when the count reaches 0 it actually cancels one such interval id setup for func2 and the others still continue to run.

You can maintain an array to capture the ids from the setInterval calls for func2 and cancel them all when count reaches 0:

(function(){
  const timer1 = setInterval(func1,3000)
  let stopper = 999
  let count = 5
  const timerIds = [];

  function func1(){
      console.log("called func1 ")
      if(count<=0){           //Count check, if zero , stop looping
          clearInterval(timer1);
          timerIds.forEach(id => clearInterval(id));
      }else{                  //if count bigger than 0
          timerIds.push(setInterval(func2,3000));
          function func2(){
              count = count - 1
              console.log("Called Func2 " + stopper)
              stopper = count 
          }
      }
}
})();

Upvotes: 0

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