char to int?

[rvr_coder]

what function copie char to int? i tried memcpy but it deosn work....
the char is the command line argument....
thx

[Gabriel Fleseriu]

#include <sstream>
//...
    const char *c = "123";
    int i;
    //...
    {
        std::stringstram s;
        s<<c;
        if((s>>i).fail()){
            //error
        }
    }
    //use i...

[NMTop40]

close to how I do it:

const char * nums( "123");

std::stringstream ss( std::string( nums ) ); // simpler way
int i;
std::string garbage;
ss >> i >> garbage;
if ( !garbage.empty() ) 
{
  // error
}
return i;

You can also use boost::lexical_cast which does pretty much that above, and throws a bad_cast exception, though personally I prefer to throw my own exception with a description of what you were trying to cast to what.

[cma]

Another option to keep in mind is using the C-function atoi() which accepts a char*.

#include <iostream>
#include <cstdlib>

using namespace std;

int main(int argc, char * argv[])
{   int n = atoi(argv[1]);
    cout << n << endl;
}

[Andreas Masur]

How to convert a numeric type to a string?...