Javascript continue statement in while loop causes an infinite loop

Question

I'm trying to create a while loop with a continue statement. However it seems to be causing an infinite loop and I can't figure out why.

The code below to me seems like it should start with the var tasksToDo at 3 then decrement down to 0 skipping number 2 on the way.

var tasksToDo = 3
while (tasksToDo > 0) {
    if (tasksToDo == 2) {
        continue;
    }
    console.log('there are ' + tasksToDo + ' tasks');
    tasksToDo--;
}

JNL · Answer 1 · 2013-08-23T13:05:48.350

3

conitnue, will go back to the while loop. and tasksToDo will never get decremented further than 2.

var tasksToDo = 3
while (tasksToDo > 0) {
if (tasksToDo == 2) {
 tasksToDo--;             // Should be here too.
 continue;
}

console.log('there are ' + tasksToDo + ' tasks');
tasksToDo--;
}

edited Aug 23 '13 at 13:05

answered Aug 23 '13 at 12:56

JNL

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score 1 · Answer 2 · answered Aug 23 '13 at 12:56

1

continue causes the loop to skip the decrement and begin all over again. Once tasksToDo hits 2, it stays 2 forever.

answered Aug 23 '13 at 12:56

score 0 · Answer 3 · answered Aug 23 '13 at 12:56

0

continue makes you go back to the beginning of the loop. You probably wanted to use break instead.

Or maybe make your decrement before the if block.

answered Aug 23 '13 at 12:56

julienc

19,087
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score 0 · Answer 4 · answered Aug 23 '13 at 12:59

It's not very clear what you're doing but from what I understand, you're trying to avoid executing logic inside while for tasksToDo = 2

var tasksToDo = 3
while (tasksToDo > 0) {
    if (tasksToDo != 2) {
        console.log('there are ' + tasksToDo + ' tasks');
    }
    tasksToDo--;
}

It wouldn't make sense to add a break in case tasksToDo = 2 since it would be easier to add that condition to the while (tasksToDo > 2).

Code here might be totally different to your real code though so I could be missing something.

score 0 · Answer 5 · answered Aug 23 '13 at 13:00

0

you are using continue; that continue your loop forever use break; to exit instead of continue;

answered Aug 23 '13 at 13:00

Neeraj Kumar Gupta

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score 0 · Answer 6 · answered Aug 23 '13 at 19:02

0

Should it be like this?

var tasksToDo = 3
while (tasksToDo > 0) {
if (tasksToDo == 2) {
 continue;
 console.log('there are ' + tasksToDo + ' tasks');
 }
tasksToDo--;
}

answered Aug 23 '13 at 19:02

Martin Hansen Lennox

2,837
2
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Yes this is the code I was given to work with but I think i see whats going on thanks to some of the answers above. – moonshineOutlaw Aug 23 '13 at 20:02

Pall Arpad · Answer 7 · 2017-11-06T09:41:22.173

0

The "continue;" statement prevent the execution of all remaining declarations in the code block.

Therefore the "tasksDo--" decrement is not executed after the loop reaches "i == 2" any more.

This creates an infinite loop!

use the "for" loop instead

the "for" loop solution for this case

var tasksToDo;

for (tasksToDo = 3; tasksToDo > 0; tasksToDo--){
    if (tasksToDo == 2) { continue; }
    console.log('there are ' + tasksToDo + ' tasks');
}

(the for loop accepts the decrement as its 3rd statement!)

edited Nov 06 '17 at 09:41

answered Nov 06 '17 at 08:49

Pall Arpad

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You should also suggest how to solve this issue by reversing some lines of the code – AngYC Nov 06 '17 at 09:12

Javascript continue statement in while loop causes an infinite loop

7 Answers7

the "for" loop solution for this case

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