Question

I’m writing for Android (Java).

I’m declaring int’s and float’s as part of an ongoing loop.

Some of them don’t need to be changed after declaration.

If I set them all to final when declaring, will things run quicker?

[Edit]

Thanks everyone. I didn’t actually expect it to make any improvements, I just noticed, after browsing the source of various large projects, it was fairly common. Cheers

Answer 1

Things will not run quicker. The final keyword is just compile time syntactic sugar.

---

If it were actually static final, then you could take benefit of compiletime calculation and inlining of the value in any refernce. So, with for example:

private static final long ONE_WEEK_IN_MILLIS = 7 * 24 * 60 * 60 * 1000L;

public void foo(Date date) {
    if (date.getTiem() > System.currentTimeMillis() + ONE_WEEK_IN_MILLIS) {
        // No idea what to do here?
    }
}

the compiler will optimize one and other so that it ends up like:

private static final long ONE_WEEK_IN_MILLIS = 604800000L;

public void foo(Date date) {
    if (date.getTiem() > System.currentTimeMillis() + 604800000L) {
        // No idea what to do here?
    }
}

If you run a decompiler, you’ll see it yourself.