int x = 1231212;
memcpy(pDVal, &x, 4);
int iDSize = sizeof(double);
int i = 0;
for (; i<iDSize; i++)
{
char c;
memcpy(&c, &(pDVal[i]), 1);
printf("%d|\n", c);
printf("%x|\n", c);
}
I used above code segment to print the hex value of each byte of a Integer. But that is not working properly. What is issue here ?
Try something like this:
void Int32ToUInt8Arr( int32 val, uint8 *pBytes )
{
pBytes[0] = (uint8)val;
pBytes[1] = (uint8)(val >> 8);
pBytes[2] = (uint8)(val >> 16);
pBytes[3] = (uint8)(val >> 24);
}
or perhaps:
UInt32 arg = 18;
array<Byte>^byteArray = BitConverter::GetBytes( arg);
// {0x12, 0x00, 0x00, 0x00 }
byteArray->Reverse(byteArray);
// { 0x00, 0x00, 0x00, 0x12 }
for the second example see: http://msdn2.microsoft.com/en-us/library/de8fssa4(VS.80).aspx
Hope this helps.
'0' != 0. No matter what Byte is, if you print this straight forward it will produce the wrong outcome, as 31 wont be printed as 1F but as 31.Just use the sprintf function. You will get a char*, so you have your array.
See the example on the webpage
itoa is a non-standard function. Consider using sprintf instead.
Your code looks awful. That's it.
memcpy(pDVal, &x, 4);
What is pDVal? Why do you use 4? Is it sizeof(int)?
int iDSize = sizeof(double);
Why sizeof(double)? May be you need sizeof(int).
memcpy(&c, &(pDVal[i]), 1); makes copy first byte of i-th array pDVal element.
printf("%d|\n", c); is not working because "%d" is waiting integer.
char as a vararg will result in integral promotion taking place, and the char will be converted to int (possibly not with the value he expects---on a lot of machines, char is signed).
"%d" is waiting integer ?? So, he's passing a char.Print like this:
printf("%d|\n", c & 0xff);
printf("%x|\n", c & 0xff);
If you are serious about the c++, this is how I would suggest to do it.
#include <sstream>
template <typename Int>
std::string intToStr(Int const i) {
std::stringstream stream;
stream << std::hex << i;
return stream.str();
}
Which you may invoke as intToStr(1231212). If you insist on getting a char array (I strongly suggest you use std::string), you can copy the c_str() result over:
std::string const str = intToStr(1231212);
char* const chrs = new char[str.length()+1];
strcpy(chrs,str.c_str()); // needs <string.h>
pDValdeclared?std::cout << std::hex << x << std::endl;that will print the hex value ofx.