For loop with setInterval

Question

I have written a for loop using setInterval. The intention was to "drip feed" the output of the for loop to the user. So basically I would like to send the console.log message every 10000ms and output it on the console of the user.

See my example below:

function longForLoop(limit) {
    for (var i = 0; i < limit; i++) {
        setInterval(() => {
            console.log("This is a long for loop. We are at " + i)
        }, 10000)
    }
}

longForLoop(10)

However, I only get the full result back as a whole?

Any suggestions what I am doing wrong here?

Appreciate your replies!

Possible duplicate of [JavaScript closure inside loops – simple practical example](https://stackoverflow.com/questions/750486/javascript-closure-inside-loops-simple-practical-example) — melpomene, Oct 11 '17 at 04:41
What problem are you really trying to solve? `setInterval()` is non-blocking so your `for` loop immediately runs to completion and meanwhile you've started `limit` timers that will repeat forever. I don't see how this does anything useful and you haven't describe what you're really trying to do. — jfriend00, Oct 11 '17 at 04:45
@jfriend00 Thank you for your reply. Please see my updated question. — Carol.Kar, Oct 11 '17 at 04:50
So you just want `setInterval(() => { console.log("This is a long for loop. We are at " + i++); }, 10000)` with no `for` loop? — melpomene, Oct 11 '17 at 04:51
Curious: why are you using `setInterval`, which schedules a never ending stream of calls (unless you explicitly clear it), rather than `setTimeout`? — Mike 'Pomax' Kamermans, Oct 11 '17 at 05:10

score 3 · Accepted Answer · answered Oct 11 '17 at 05:11

Don't use setInterval with for loop in these cases as the setInterval will run without condition. use either one of these.I used setInterval without loop and I am using clearInterval once the condition reaches

function longForLoop(limit) {
  var i = 0;
  var ref = setInterval(() => {
    console.log("This is a long for loop. We are at " + ++i);
    if (i == limit) clearInterval(ref);
  }, 1000);
}

longForLoop(10);

In other ways you could also use setTimeout with recursive function

kumbhani bhavesh · Answer 2 · 2017-10-11T05:04:32.083

0

You can use setTimeout instead of setInterval. Look at my example:

function longForLoop(limit) {
for (var i = 0; i < limit; i++) {
    (function(j) {
       setTimeout(function() {
        console.log('j',j);      
       }, 100 + (1000 * j));
  })(i);
 }
}

longForLoop(10)

edited Oct 11 '17 at 05:04

answered Oct 11 '17 at 05:00

kumbhani bhavesh

2,189
1
15
26

SYED SHAH · Answer 3 · 2017-10-11T05:22:22.597

-1

The variable i is bound to the value outside your anonymous function. Use code below which passes value of i to function

function longForLoop(limit) {
    for (var i = 0; i < limit; i++) {
        function innerFunction(valOfi)
        {
                console.log("This is a long for loop. We are at " + valOfi);
        }
        setInterval(innerFunction(i) , 10000)
    }
}

longForLoop(10)

edited Oct 11 '17 at 05:22

answered Oct 11 '17 at 04:56

SYED SHAH

84
6

For loop with setInterval

3 Answers3