huh == Boolean TRUE made it go away kotlinlang #announcements

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Title

adam-mcneilly

02/07/2019, 2:56 PM

huh == Boolean.TRUE made it go away

Shawn

02/07/2019, 2:57 PM

another oddity to file away for later 🤔

😂 1

adam-mcneilly

02/07/2019, 2:57 PM

lmao yep

Wouldn't it still need to unbox to perform this comparison? 🤔

Shawn

02/07/2019, 2:58 PM

You know, I’ve been wrangling with that in my head

Wait, no, not in Java since

==

is identity

Hm, wait, no, that probably isn’t explaining it properly either lmao

adam-mcneilly

02/07/2019, 3:00 PM

lmao

Shawn

02/07/2019, 3:00 PM

I might fire up the bytecode viewer and see what’s different about primitive comparisons

adam-mcneilly

02/07/2019, 3:01 PM

I am going to hardcode this property as null and see if it crashes

👨‍🔬 1

It could be a primitive thing though. This could work in the same way that getCount() == 2 works, for example.

👨‍🔬 I come back to report that

config.isTransparentToolbar() == Boolean.TRUE

will not crash if it's null. Thanks for all the help.

karelpeeters

02/07/2019, 6:44 PM

I would not do that, ever.

java.lang.Boolean

isn't a proper "dualton", you can create new instances: https://docs.oracle.com/javase/7/docs/api/java/lang/Boolean.html#Boolean(boolean)

Boolean(true) != Boolean.TRUE

:java:

Shawn

02/07/2019, 6:44 PM

aw beans

why is that constructor even public

karelpeeters

02/07/2019, 6:45 PM

I don't understand why they did that either 🤔

Probably from a time when effective Java hadn't come out yet and factory methods weren't popular yet. 😒imple_smile:

adam-mcneilly

02/07/2019, 7:28 PM

Oh wow. So then what's an alternative to handling this unboxing warning?

Shawn

02/07/2019, 7:29 PM

Probably something like

Boolean.TRUE.equals(config.isTransparentToolbar())

if I had to guess

👍 1

it looks terribly unintuitive, though, like I’d be pretty bewildered if I came across that line had Karel not explained the awfulness of

Boolean

to us

louiscad

02/07/2019, 7:33 PM

FYI,

Boolean

boxes are cached… because there's only two values to cache. For other primitives (numbers), all values that cover

Byte

(-128 to 127) are cached, at least on Android.

karelpeeters

02/07/2019, 7:33 PM

Boolean.valueOf(x)

is cached,

Boolean(x)

can't be.

Bigger question is why is your boolean nullable? Shouldn't that be an enum or something?

adam-mcneilly

02/07/2019, 8:56 PM

It's a model object that I get from the server. I make all fields in my data class nullable so it can handle the server not supplying them or possibly sending null.

karelpeeters

02/07/2019, 8:56 PM

Okay, makes sense 😒imple_smile:

🙂 1

adam-mcneilly

02/07/2019, 9:01 PM

Thank you for your help!

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