Java 8 way to repeat a block of code x times

Question

Maybe a normal for loop is still the right way but I wanted to see if there is a more succinct way to do it in java 8.

 for (int i = 0; i < LIMIT; i++) {
     // Code
 }

Is there a more java 8 way to do this. I don't actually need i just need to repeat something x number of times.

Thanks, Nathan

http://stackoverflow.com/questions/18532488/does-java-8-provide-a-good-way-to-repeat-a-value-or-function?rq=1 maybe this? — Brandon Ling, Jun 11 '15 at 14:24
See also [“How to create nice iterations in Java 8”](http://stackoverflow.com/q/27779568/2711488) — Holger, Jun 11 '15 at 14:33

Voo · Accepted Answer · 2015-06-11T14:26:48.747

19

The best way I can see on how to do this would be something like IntStream.range(0, LIMIT).forEach($ -> code).

edited Jun 11 '15 at 14:26

answered Jun 11 '15 at 14:24

Voo

1

Could you clarify why you use dollar sign for the identifier? Is it a convention to use `$` when it's unused. Also, could this ever cause a conflict (for the same reason `$` usage in identifiers is cautioned) – swalog Sep 28 '15 at 13:12
1

@swalog In other languages `_` is used to signify unused parameters, but that isn't allowed in Java, so just pick what you want. I'm not the only one using it (see Peter's answer), but I doubt there's any wide spread idiom. The compiler uses `$` for inner classes (no risk there), a few special fields like `$assertionsDisabled ` and presumably (not checked) methods created from lambdas (again no risk there). Pick whatever you want. – Voo Sep 28 '15 at 13:59
You will to do a lot if the 'code' called in the Lambda function throws checked exception. You cannot throw a checked exception in Java8 Lambda. – Shubham Jun 20 '17 at 08:28

score 9 · Answer 2 · answered Jun 11 '15 at 14:27

9

One of the reasons to use IntStream is to add parallel-ism, assuming you understand the impact of this.

IntStream.range(0, LIMIT).parallel().forEach($ -> {
    // some thing thread safe.
});

answered Jun 11 '15 at 14:27

Peter Lawrey

2 Answers2