Questions tagged [unsigned-char]
321 questions
217
votes
8 answers
uint8_t can't be printed with cout
I wrote a simple program that sets a value to a variable and then prints it, but it is not working as expected. My program has only two lines of code:
uint8_t a = 5;
cout << "value is " << a << endl;
The output of this program is value is , i.e.,…
CoderInNetwork
- 2,923
- 4
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- 39
85
votes
17 answers
how do I print an unsigned char as hex in c++ using ostream?
I want to work with unsigned 8-bit variables in C++. Either unsigned char or uint8_t do the trick as far as the arithmetic is concerned (which is expected, since AFAIK uint8_t is just an alias for unsigned char, or so the debugger presents it.
The…
Nathan Fellman
- 122,701
- 101
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- 319
66
votes
3 answers
When is uint8_t ≠ unsigned char?
According to C and C++, CHAR_BIT >= 8.
But whenever CHAR_BIT > 8, uint8_t can't even be represented as 8 bits.
It must be larger, because CHAR_BIT is the minimum number of bits for any data type on the system.
On what kind of a system can uint8_t be…
user541686
- 205,094
- 128
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- 886
64
votes
3 answers
Why can't I static_cast between char * and unsigned char *?
Apparently the compiler considers them to be unrelated types and hence reinterpret_cast is required. Why is this the rule?
Nick
- 2,821
- 5
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- 35
58
votes
6 answers
Why does the complement behave differently through printf?
I was reading a chapter on bitwise operators, I came across 1's complement operator program and decided to run it on Visual C++.
int main ()
{
unsigned char c = 4, d;
d = ~c;
printf("%d\n", d);
}
It gives the valid output: 251
Then instead…
Sanketssj5
- 655
- 5
- 17
26
votes
6 answers
cout not printing unsigned char
I am working on below code:
#include
#include
using namespace std;
main() {
unsigned char a;
a=1;
printf("%d", a);
cout<
Hitesh Menghani
- 977
- 1
- 6
- 14
23
votes
7 answers
C - unsigned int to unsigned char array conversion
I have an unsigned int number (2 byte) and I want to convert it to unsigned char type. From my search, I find that most people recommend to do the following:
unsigned int x;
...
unsigned char ch = (unsigned char)x;
Is the right approach? I ask…
Jake
- 16,329
- 50
- 126
- 202
20
votes
6 answers
Bytewise reading of memory: "signed char *" vs "unsigned char *"
One often needs to read from memory one byte at a time, like in this naive memcpy() implementation:
void *memcpy(void *dest, const void *src, size_t n)
{
char *from = (char *)src;
char *to = (char *)dest;
while(n--) *to++ = *from++;
…
Philip
- 5,795
- 3
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- 68
19
votes
2 answers
std::move between std::string and std::vector
I am working with 2 libraries. One takes in and returns std::strings while the other uses std::vectors.
It would be good if I could steal the underlying arrays from std::string and std::vector and be able to move them…
genjix
- 852
- 2
- 11
- 21
16
votes
5 answers
How to sprintf an unsigned char?
This doesn't work:
unsigned char foo;
foo = 0x123;
sprintf("the unsigned value is:%c",foo);
I get this error:
cannot convert parameter 2 from
'unsigned char' to 'char'
Christoferw
- 741
- 3
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- 20
15
votes
3 answers
How to print unsigned char[] as HEX in C++?
I would like to print the following hashed data. How should I do it?
unsigned char hashedChars[32];
SHA256((const unsigned char*)data.c_str(),
data.length(),
hashedChars);
printf("hashedChars: %X\n", hashedChars); // doesn't seem to…
louis.luo
- 2,921
- 4
- 28
- 46
14
votes
3 answers
Put bytes from unsigned char array to std::string using memcpy() function
I have std::string variable. And I need to put some bytes from array of unsigned chars to it. I know the first byte and the the legth.
I can use the std::string::assign function. I've done it.
But I want to solve that issue in a right way using the…
Oleksandr Balabanov
- 629
- 1
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- 30
13
votes
1 answer
Copy unsigned char array
What would be the best way to copy unsigned char array to another?
For example:
unsigned char q[1000];
unsigned char p[1000];
strcpy (q,&p);
The above code does not work, it gives me error saying "cannot convert parameter 1 from unsigned char…
user2829
- 451
- 1
- 7
- 21
13
votes
4 answers
Invalid conversion from unsigned char* to char*
Here is a code -
1 int main(int argc, char *argv[])
2 {
3 signed char S, *psc;
4 unsigned char U, *pusc;
5 char C, *pc;
6
7 C = S;
8 C = U;
9
10 pc = psc;
11 pc = pusc;
12
13 return 0;
14…
nightlytrails
- 2,448
- 3
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- 33
11
votes
1 answer
P/Invoke, c#: unsigned char losing a byte
Im working towards a dll file for a software's SDK and i'm trying to call a function to get information about the host of the software.
there are two unsigned char variables(HostMachineAddress, HostProgramVersion) in the struct the function wants…
Tistatos
- 641
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