string to integer

[quickcur@yahoo.com]

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

Thanks,

qq

[Victor Bazarov]

Re: string to integer

quickcur@yahoo. com wrote:[color=blue]
> If I have a string in Hex, e.g., "0xff", how can I turn it into
> numbers?[/color]

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

[Alan]

Re: string to integer


<quickcur@yahoo .com> wrote in message news:1103742581 .120693.155210@ z14g2000cwz.goo glegroups.com.. .[color=blue]
> If I have a string in Hex, e.g., "0xff", how can I turn it into
> numbers?[/color]

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]

Re: string to integer

quickcur@yahoo. com wrote:[color=blue]
> If I have a string in Hex, e.g., "0xff", how can I turn it into
> numbers?[/color]

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::istringstr eam n_stream(n_stri ng);
n_stream.unsetf (std::ios_base: :dec);

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