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Converting Hexdecimal numbers....

Narasimha Rao B.
Ranch Hand

Joined: Aug 26, 2002
Posts: 205
Hi,
1) Can, any of you explain how to convert big Hex decimal numbers to decimal. For ex, how will you convert 0xffffffc9 to decimal number.
2)
byte b = 0; int i=0;
Is there any short cut method is there to solve the below expression,
b = (byte)(b + (b - (i = 0xffffffc9)))
Thanks in Advance....


Narasimha
Ryan Wilson
Ranch Hand

Joined: Apr 16, 2003
Posts: 65
byte b = 0; int i=0;
b = (byte)(b + (b - (i = 0xffffffc9)))
0xffffffc9 is going to be negative because the leftmost bit is 1. (f = 1111)
so the number is going to be 111........11001001
because c = 1100 and 9 = 1001.
Flip the bits and add 1.
000...........00110110 + 1 = 000....00110111 = -55
b = (byte)(b + (b - (-55)))
b = (byte)(b + 55)
b = (byte)(0 + 55)
b = 55
I hope this helps
Bert Bates
author
Sheriff

Joined: Oct 14, 2002
Posts: 8815
    
    5
Narasimha -
First here's a link that might help...
http://www.coderanch.com/t/241326/java-programmer-SCJP/certification/Converting-Hexadecimal-literals
The key points are:
1 - For anyone new to JavaRanch - the exam won't ask you to convert big hex or octal or binary numbers!
2 - The exam WILL ask you to understand how two's complement numbers are stored, and how the >>, >>>, << operators affect these two's complement numbers.

- Bert
UnderSecretary to the Minister of Keep your Focus


Spot false dilemmas now, ask me how!
(If you're not on the edge, you're taking up too much room.)
Jessica Sant
Sheriff

Joined: Oct 17, 2001
Posts: 4313

if you need some more info -- check out our handy dandy search feature. I did a search for "convert hexadecimal" and got a lot of good hits.
Enjoy!


- Jess
Blog:KnitClimbJava | Twitter: jsant | Ravelry: wingedsheep
 
It is sorta covered in the JavaRanch Style Guide.
 
subject: Converting Hexdecimal numbers....