how do I create an infinite loop in JavaScript

Question

I want to create an infinite loop in JavaScript.

What are some ways to achieve this:

eg

for (var i=0; i<Infinity; i++) {}

This question is not a duplicate of https://stackoverflow.com/questions/5835126/javascript-infinite-loop ... even though the titles are similar — rolfl, Jul 30 '19 at 18:29

score 79 · Answer 1 · edited Aug 01 '20 at 22:06

79

You can also use a while loop:

while (true) {
    //your code
}

edited Aug 01 '20 at 22:06

Adrian Mole

answered Jul 27 '14 at 02:54

Pran

2

Won't this throw an exception? – nunop Sep 12 '16 at 22:18
8

This will block the Javascript execution in the page, leading to a browser dialog asking to stop or debug the script. It won't work – Alberto S. Jun 15 '17 at 11:31
5

@Alberto Except if you are not programming for browsers – JoseLinares Aug 29 '19 at 16:10
2

@Alberto It's absolutely ok inside generator functions. – Denis Giffeler Mar 02 '20 at 07:55
In a case, if it is expected to execute in a browser, a better way to implement an infinite loop Is using setTimeout or setInterval function. This post contains more descriptive details about that. (https://nextcsguide.com/javascript/javascript-infinite-loops-that-work-on-browsers/) – Ravindu Sachintha Mar 24 '21 at 02:14

score 74 · Answer 2 · answered Jul 27 '14 at 02:50

74

By omitting all parts of the head, the loop can also become infinite:

for (;;) {}

answered Jul 27 '14 at 02:50

Elise Chant

5

That is better than while(true){}: if you use ESLint, it won't trigger http://eslint.org/docs/rules/no-constant-condition. – alexgula Oct 10 '16 at 10:30
4

For some reason, I just hate how this looks in my code. So cryptic. I wonder if there's a more semantic way to do it? But yeah, seems like the way to go in this case! – counterbeing Nov 08 '17 at 21:17
This one seems a better choice, since some code optimizers (like Webpack Terser plugin) spam with warnings like `Condition always false` and `Dropping unreachable code` when using the `while (true)` variant. – ololoepepe Jul 06 '19 at 15:39
3

You can break `for(;;) {}` loops with `true` between the semicolons `for(;true;) { if(condition) break; //do work }`. – T.CK Dec 13 '19 at 16:14
I like it just because it's unique :D – gilad905 Mar 23 '21 at 21:51

2 Answers2