An unsigned variable is a variable that can only represent non-negative numbers.
An unsigned variable is a variable that can only represent non-negative numbers, as opposed to a signed variable which can represent both positive and negative numbers.
Questions tagged [unsigned]
1251 questions
8
votes
3 answers
Does the unsigned keyword affect the result of sizeof?
Do C and C++ guarantee that the unsigned equivalent of a type has the same size?
Example:
size_t size = sizeof(unsigned int);
Is the unsigned completely moot here?
typ1232
- 5,535
- 6
- 35
- 51
8
votes
5 answers
difference between unsigned short int and unsigned short
Is there a difference between unsigned short int and a unsigned short decleration in c and if so, what is it please ? I tried looking online, but couldn't find anything worthwhile.
unsigned short int x1;
unsigned short x2;
Lastly, if there is a…
Goaler444
- 2,591
- 6
- 35
- 53
8
votes
2 answers
Declare an "unsigned T"
I want to use unsigned T in a template:
template
void signed2unsigned(const T* source, unsigned T* dest, size_t n)
{
do
{
intmax_t s=*source;
s+=min(*source);
*dest=s;
++dest;
…
user877329
- 6,717
- 8
- 46
- 88
8
votes
7 answers
How do you get an unsigned long out of a string?
What's the safest and best way to retrieve an unsigned long from a string in C++?
I know of a number of possible methods.
First, converting a signed long taken from atol.
char *myStr; // Initalized to some value somehow.
unsigned long n =…
Daniel Bingham
- 12,414
- 18
- 67
- 93
8
votes
1 answer
Will 'comparison between signed and unsigned integer expressions' ever actually result in errors?
Often an object I use will have (signed) int parameters (e.g. int iSize) which eventually store how large something should be. At the same time, I will often initialize them to -1 to signify that the object (etc) hasn't been setup / hasn't been…
DilithiumMatrix
- 17,795
- 22
- 77
- 119
7
votes
2 answers
Whats the working difference between a signed char pointer and an unsigned one?
I can understand the difference between a signed char and an unsigned one. But dont the pointers of the corresponding type equivalent in their operation? Cos sizeof(char) and sizeof(unsigned char) is always the same ( Or are there any counter…
Pavan Manjunath
- 27,404
- 12
- 99
- 125
7
votes
7 answers
Does unsigned math require more CPU instructions?
Take an C++ integral variable i, and suppose that you're multiplying its value by 2.
If i has signedness, I believe that the operation is somewhat equivalent, at least mathematically, to:
i = i << 1;
But if i's type is unsigned, then since unsigned…
Lightness Races in Orbit
- 378,754
- 76
- 643
- 1,055
7
votes
4 answers
Convert int to unsigned short java
I have written a .obj parser in java to modelize 3D objects on iPhone. I would like to export the data as a binary file, which must be as small as possible. I have plenty of indices that would fit a unsigned short, but they are represented as int in…
Friedrik
- 389
- 1
- 2
- 12
7
votes
1 answer
Signed variant of size_t in standard C++ library
Is there a signed variant of size_t in standard C++? Meaning exactly same bit size as size_t but signed.
Of course I can do:
#include
using signed_size_t = std::make_signed_t;
but maybe there is already similar definition…
Arty
- 14,883
- 6
- 36
- 69
7
votes
2 answers
If an integer is signed by default, why does the signed keyword exist?
I'm curious why the signed keyword exists because I believe most integers and other variables are signed by default. Putting the signed keyword before int virtually does nothing. What is it used for, and why does it exist?
Comyar D
- 172
- 2
- 9
7
votes
3 answers
Should I use "mul" or "imul" when multiplying a signed number to an unsigned number?
I have found out that both mul and imul can be used to multiply a signed number to an unsigned number.
For example:
global _start
section .data
byteVariable DB -5
section .text
_start:
mov al, 2
imul BYTE [byteVariable]
You can replace imul…
user8315006
7
votes
4 answers
Compiler warning for unary operation on unsigned int
I have this sample code which generates the following warning (VS2008 compiler with SP1):
warning C4146: unary minus operator
applied to unsigned type, result still
unsigned
Code:
void f(int n)
{
}
int main()
{
unsigned int n1 = 9;
…
Naveen
- 74,600
- 47
- 176
- 233
7
votes
5 answers
Unsigned negative primitives?
In C++ we can make primitives unsigned. But they are always positive. Is there also a way to make unsigned negative variables? I know the word unsigned means "without sign", so also not a minus (-) sign. But I think C++ must provide it.
Martijn Courteaux
- 67,591
- 47
- 198
- 287
7
votes
1 answer
How to convert an NSString to an unsigned int in Cocoa?
My application gets handed an NSString containing an unsigned int. NSString doesn't have an [myString unsignedIntegerValue]; method. I'd like to be able to take the value out of the string without mangling it, and then place it inside an NSNumber.…
Dave
- 12,408
- 12
- 64
- 67
7
votes
4 answers
Array's index and argc signedness
The C standard (5.1.2.2.1 Program startup) says:
The function called at program startup
is named main. [...]
It shall be defined with a
return type of int and with no
parameters:
int main(void) { /* ... */ }
or with two parameters [...]…
Bertrand Marron
- 21,501
- 8
- 58
- 94