Thread: converting a string to an int or double..

http://www.parashift.com/c++-faq-lit....html#faq-39.2

1. Use the atof function:

Code:

#include <iostream>
#include <string>
#include <cstdlib>

using namespace std;

int main()
{
    string str("19.874");
    double d;

    // Use atof to convert string to double
    d = atof(str.c_str());

    // Output double value
    cout << d << endl;

    return 0;
}

2. Use stringstreams:

Code:

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

using namespace std;

int main()
{
    string str("19.874");
    stringstream sstr(str);
    double d;

    // Extract double value from stringstream
    sstr >> d;

    // Output double value
    cout << d << endl;

    return 0;
}

http://www.cppreference.com/stdstring/atof.html

this is how you can do it in C not C++ hope it helps

[edit1]
took me a little while to find the correct link.
if you saw this with the old link, sorry to confuse you.

here is the index to the site with good details
http://www.cppreference.com/index.html

if all else fails google it.
[/edit1]

using <sstream>:

Code:

#include <sstream>
 
using namespace std;
 
string makeString(double d)
{
	ostringstream ss;
	ss<<d<<flush;
	return ss.str(); 
}

here is another link i found that might be of assistance to you.
all i did again was run a search on google to find it.
it uses stringstream to convert from and to the formats your looking for.
http://pegasus.rutgers.edu/~elflord/...ingstream.html