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# Negative int

Ranch Hand
Posts: 122
Hi,

Given an int, how to determine whether it is positive or negative. For e.g. int x = -1; How to determine x is negative?

Thanks,
Visu Nekk

Ranch Hand
Posts: 433
look at the bit pattern of x..!!

if right most bit is 1, this means it is negative..!!!

x = -1 ===> 11111111 11111111 11111111 11111111

Wanderer
Sheriff
Posts: 18671
I'm not sure the original poster was thinking of bit patterns. The answer might be as simple as

Deepak Chopra
Ranch Hand
Posts: 433
if he was asking this..!! he could have tested it first..before posting!!

Jim Yingst
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Posts: 18671
This is the beginner section. Maybe he doesn't know how to use <, or write an if statement, or print the result. Who knows?

Sheriff
Posts: 23286
46
And also, if the rightmost bit of a binary integer is 1, that means it's an odd integer, not that it's a negative integer.

Marshal
Posts: 57482
175

Originally posted by Paul Clapham:
And also, if the rightmost bit of a binary integer is 1, that means it's an odd integer, not that it's a negative integer.

You mean leftmost, surely.

BTW: If you get a binary String with the Integer.toBinaryString() methods, it excludes leading 0s, so it always has 1 as the leftmost displayed digit. You will have to use a for loop and the insert method of StringBuilder (or similar) to pack it with 0s from the left.

For always has 1 read "almost always has 1" The value of 0 wouldn't have a 1 in![/edit]
[ January 30, 2008: Message edited by: Campbell Ritchie ]

Jim Yingst
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Posts: 18671
[PC]: And also, if the rightmost bit of a binary integer is 1, that means it's an odd integer, not that it's a negative integer.

[CR]: You mean leftmost, surely.

I'm pretty sure he meant rightmost. Leftmost is what Sunny should have said, but rightmost is what he did say. Paul was commenting on that.

Deepak Chopra
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Posts: 433
Ohh I am sorry, What I meant was left most bit..!!
Being a left handed person i often got confusion regarding that..! as My left is actually my right hand..but for other it is left hand..!!

Campbell Ritchie
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Posts: 57482
175
Yes, you are right; it was Sunny Jain who ought to have said leftmost.

Ranch Hand
Posts: 3389

Originally posted by Sunny Jain:
Ohh I am sorry, What I meant was left most bit..!!
Being a left handed person i often got confusion regarding that..! as My left is actually my right hand..but for other it is left hand..!!

Good that the confusions are resolved earlier here. Also i believe it does not make any confusions wiht L-R , R-L associativities

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