Hi Johann,
Mark Burton schrieb:
As the object sizes are rounded to multiples of 8, it looks like a case of buy one, and get 7 for free!
Yes, just tried that and the same amount of memory is used for 1 boolean and 8 booleans.
Sorry, I cannot confirm this.
But your figures below do confirm that, don't they?
Out of personal interest I have run your test programm with OpenJDK6 and get following results:
johann@ubuntu910:~/workspace>java Test Size for LotsOfBooleans: 87978536 Average size: 87.978536 Size for LotsOfInts: 336000000 Average size: 336.0
This means 1Byte/Boolean and 4Bytes/Int plus 8 Byte per Instance of object, as I expected it. Maybe I had to run the vm with a java option?
Yes, but if you only have 1 boolean in the class with the ints it still uses 336 bytes. So you get 7 for free! If you add no booleans to the class, the size is 328. So I guess that's why they say that some people think the class is half empty while the others say that the class is half full! Cheers, Mark