store 0xFFFFFFFF

[Mahesh x Bogadi]

Hi All,

I need to stored 0xFFFFFFFF as an integer.
I tried using long without success.

Please help.

[Manuel Moons]

Ok, so why don't you store it as an integer. It does not exceed the allowed value for an int.

[Stuart Gray]

Well, that depends. Remember that although ints are 32 bits (4 bytes, like the number above), they are always signed so we only have the range of approximately +/- 2^31

[Ulf Dittmer]

It is possible to store the bit pattern consisting of 32 ones as an int, but Java will interpret that to mean "-1", because all numbers having the most significant bit set are negative.

I tried using long without success.

What does this mean? Have you tried:

long num = 0xffffffffl;

(That's a leading zero before the x, and a trailing lowercase letter L).
[ August 12, 2005: Message edited by: Ulf Dittmer ]

[Norm Radder]

Another way to get what java might consider as negatively signed data into an int without the spreading of the sign bit is by ANDing it with the mask: 0xFF to insure the high order bits are set to 0.

[Steve Morrow]

(That's a leading zero before the x, and a trailing lowercase letter L).

It doesn't have to be lowercase; in fact it's preferable to use the uppercase "L" so you don't confuse it with the number "1"; I believe that's one of Bloch's puzzlers...

[Steve Morrow]

Originally posted by Norm Radder:
Another way to get what java might consider as negatively signed data into an int without the spreading of the sign bit is by ANDing it with the mask: 0xFF to insure the high order bits are set to 0.

Maybe I'm not understanding what you're proposing, but that will mask off everything but the 8 lowest bits. Is that your intended behavior? How is that getting negatively signed data into an int without "spreading the sign bit"?

[Layne Lund]

Originally posted by Mahesh Bogadi:
Hi All,

I need to stored 0xFFFFFFFF as an integer.
I tried using long without success.

Please help.

int x = 0xFFFFFFFF;

What's wrong with this? As noted above, Java will interpret this as -1 if you simply use it as an int, but if your are doing bit manipulations why does this matter? Maybe I don't understand your question. If you can explain what you have tried and why it didn't seem to work, we can help a lot more easily. At the moment all we can do is guess what your problem is, but that isn't a very efficient way of answering your question.

Layne