Preferred method of integer casting?

[ajacksified]

It's a small thing, but we should probably be consistent here, too. What's the best way to cast to integers? I have the habit of bitshifting by 0 "15" >> 0; it's one of the more performant ways to do it, and it's concise, but it also isn't super obvious.

[hshoff]

I always do +'15', open to changing this if there's a more preferred way.

see Numbers: https://github.com/airbnb/javascript#type-coercion

[hshoff]

Here's a jsPerf Coercion vs. Casting vs. Bitshift

Looks like casting with parseInt() is the fastest.

[ajacksified]

parseInt looks good.

[ssorallen]

I didn't expect bitshifting to be so much slower than parseInt.

I always use parseInt because it's explicit about what you're doing. +'1' and '1' >> 0 work, but they're tricks. If you are parsing an integer, you can't get more explicit than a function called "parseInt".

[ssorallen]

If we go with parseInt, we should enforce always including a radix.

// Bad
parseInt('123');

// Good
parseInt('123', 10);

[ajacksified]

Took a look with other browsers- bitshift is drastically better on FF and IE. Not sure if buggy test result.

[hshoff]

Woah, what's Webkit got against bitshift?

I vote we go with parseInt because it's explicit.

But it should be allowed to do bitshifting if you need to performance boost on lots of strings to ints. Maybe just leave a comment why you think you need to bitshift over being explicit?

[clizzin]

👍 for parseInt in general for clarity, and bitshifting with an explanatory comment when necessary for performance — although IMO it takes a lot to justify performance > clarity. But that's just bikeshedding.

Also 👍 for including a radix when calling parseInt. It is ugly and verbose, but it's a hell of a lot better than a prefixed 0 ruining your day.

[reissbaker]

👍 for parseInt with a radix. Bitshifts aren't very clear, and for our types of applications VM execution speed is a non-concern.

But it should be allowed to do bitshifting if you need to performance boost on lots of strings to ints.

Fair, if you have profiling that proves parseInt is a major performance bottleneck. But optimizing without profiling is a bad idea.