string to integer

[quickcur]

If I have a string in Hex, e.g., "0xff", how can I turn it into
numbers?

Thanks,

qq

 

[Victor Bazarov]

If I have a string in Hex, e.g., "0xff", how can I turn it into
numbers?

Discard the '0x' and use strtod to convert the rest.

 

[Alan]

If I have a string in Hex, e.g., "0xff", how can I turn it into
numbers?

long strtol( const char *s, char **endptr. int radix) in stdlib.h

If radix is zero and first char is "0" and second is "x" (or "X"), string is
interpreted as hexadecimal.

long num = strtol("0xff", NULL, 0);

 

[Robert Swan]

If I have a string in Hex, e.g., "0xff", how can I turn it into
numbers?

if none of the ios_base::hex/dec/oct are set on a std input stream then
the prefix determines the base for string formatting

#include <iostream>
#include <string>
#include <sstream>

int main() {
std::string n_string("0xff");
std::istringstream n_stream(n_string);
n_stream.unsetf(std::ios_base::dec);

int result;
n_stream >> result;
std::cout << result << std::endl; // should output 255
}