C ++ equivalent

Question

A friend of mine sent me his program. It uses "stod" to convert the string to double. Is there any other way to do such a thing?

My correspondent shows an error: "Stod has not been declared in this area"

I turned #include <string> #include <cstdlib>

it on but nothing changed.

My compiler doesn't use C ++ 11 features. By the way, this program was prepared as a school project without using C ++ 11.

+3

c ++

Antoni Bąk May 25 '15 at 11:48 PM

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2 answers

Steephen · Answer 1 · 2015-05-25T23:58:32+0000

std::atof()

is a swift option passed from the C language, you must enable <cstdlib>

it to use it.

Otherwise, you can use std :: stringstream to handle it.

    #include<sstream> 

    std::string value="14.5";
    std::stringstream ss;
    ss<< value;

    double d=0.0;
    ss>>d;

RedAgito · Answer 2 · 2015-05-25T23:55:38+0000

A quick and dirty way to convert a string to double would be

#include <sstream>
#include <string>

std::string text;
double value;
std::stringstream ss;
ss << text;
ss >> value;

But be aware of the error required to verify the correct conversion

EDIT: you will need to test the string to fail with

if (ss.fail()) { /* error */ }

Source http://www.cplusplus.com/reference/istream/istream/operator%3E%3E/