Visit Our UNIX and Linux User Community


Signed and unsigned intergers


 
Thread Tools Search this Thread
Top Forums Programming Signed and unsigned intergers
# 1  
Old 10-16-2012
Signed and unsigned intergers

when a date type is considered signed and unsigned is that simple referring to - for signed and positive numbers for unsigned? Further if that is the case would mutiplying and dividing ect where 2 signed numbers, like (-2)*(-2) = 4 result in a unsigned.
# 2  
Old 10-16-2012
When data type is signed it means that the bit order represents negative, zero and positive values, when it is unsigned it means it can represent only zero and positive values. For example signed byte can represent values between -127 and 127, unsigned byte can represent values from 0 to 255.
# 3  
Old 10-17-2012
The difference between signed and unsigned isn't the minus symbol, it's how the numbers are interpreted by the processor.

An unsigned signed 8-bit number:
Code:
binary 1 1 1 1 1 1 1 1 = 2^7 + 2^6 + 2^5 + 2^4 + 2^3 + 2^2 + 2^1 + 2^0 = 255

A signed 8-bit number:
Code:
binary 1 1 1 1 1 1 1 1 = (-2^7) + 2^6 + 2^5 + 2^4 + 2^3 + 2^2 + 2^1 + 2^0 = -1

This allows easy subtraction as well as addition through two's-complement arithmetic -- add the opposite plus one to subract.
# 4  
Old 10-17-2012
For unsigned interger the MSB(most significant bit) is '0'.
For signed interger the MSB(most significant bit) is '1'.

For example,(I) 12 is represented as 0000 1100
(II)-12 is represented as 1111 0100

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. OS X (Apple)

Unsigned to signed, error?...

Hi guys... Macbook Pro, 13", circa August 2012, OSX 10.7.5, default bash terminal. I require the capability to convert +32767 to -32768 into signed hex words... The example piece code below works perfectly except... #/bin/bash # sign.sh # Unsign to sign... while true do # I have used... (2 Replies)
Discussion started by: wisecracker
2 Replies

2. Programming

Unable to assign zero to unsigned character array

Hi, I am unable to assign value zero to my variable which is defined as unsigned char. typedef struct ABCD { unsigned char abc; unsigned char def; unsigned char ghi; } ABCD; typedef ABCD *PABCD; In my Por*C code, i assign the values using memcpy like below ... (3 Replies)
Discussion started by: gthangav
3 Replies

3. Programming

Comparing unsigned char bits.

/******************************************************************************/ /* Printing an unsigned character in bits */ #include <stdio.h> void display_bits ( unsigned char ); int main() { unsigned char x; /*... (15 Replies)
Discussion started by: robin_simple
15 Replies

4. Programming

Help with understanding ( int, char, long, short, signed, unsigned etc.... )

My question is simple: When should I use a long, int, char, unsigned/signed variables?? When I declare a variable "unsigned;" what did I do it??? Why would I delcare an integer "long" or "short" ( unsigned or signed)?? Any examples of when things like "unsigned", "long", "short" etc...... (6 Replies)
Discussion started by: cpp_beginner
6 Replies

5. UNIX for Advanced & Expert Users

"Signed Linux" - Only executing signed programs

Hey folks, not sure whether this or the security board is the right forum. If I failed, please move :) So here's the problem: I need to build a Linux environment in which only "signed" processes are allowed to run. When I say signed I don't mean a VeriSign signature like you know it from... (5 Replies)
Discussion started by: disaster
5 Replies

6. Shell Programming and Scripting

add signed and unsigned numbers- awk help

Hi All, I have written the below to add the numbers in a column. Postive numbers are unsigned and negative numbers are signed in the file. After the below cmd I am getting -0.00 , instead of 0.00. Can someone guide me on what I am missing in the cmd. grep '^L' $FileName| awk -F"|" ' {... (7 Replies)
Discussion started by: gsjdrr
7 Replies

7. Red Hat

cast from const void* to unsigned int loses precision

Hello everey one, here i am attempting to compile a c++ project .it's throughing the following errors. my machine details are as follows: Linux chmclozr0119 2.6.18-53.el5 #1 SMP Wed Oct 10 16:34:19 EDT 2007 x86_64 x86_64 x86_64 GNU/Linux errors: ===== Generating... (0 Replies)
Discussion started by: mannam srinivas
0 Replies

8. UNIX for Dummies Questions & Answers

So, like, I signed on with a new hosting company...

... and there was absolutely nothing installed except fedora and ssh. I used yum to install vsftp and httpd, both start and ps shows they're running, and yet I can't connect with either of them. Where on earth or in redhat do I begin looking to unravel this one? I've overseen a server before but... (3 Replies)
Discussion started by: Bobby
3 Replies

9. Programming

to get the correct value with unsigned int

hi, Please help me with the following code to get the difference in values. struct a{ int b1; int c1; char d1; } main() { unsigned int b=10; unsigned int c; c = b - (unsigned int )sizeof(a); printf("%d",c); } Here c returns some junk value. How can i get the... (2 Replies)
Discussion started by: naan
2 Replies

10. Programming

Unsigned int

How can I store and/or print() a number that is larger than 4 294 967 295 in C? is int64_t or u_int64_t what I need ? if, so how can I printf it to stdout? (2 Replies)
Discussion started by: nimnod
2 Replies

Featured Tech Videos