Converting Double to String in C++

Question

I am having some issues trying to convert a double to C++ string. Here is my code

std::string doubleToString(double val)
{
    std::ostringstream out;
    out << val;
    return out.str();
}

The problem I have is if a double is being passed in as '10000000'. Then the string value being returned is 1e+007

How can i get the string value as "10000000"

How about some of the examples from the following: http://www.codeproject.com/KB/recipes/Tokenizer.aspx They are very efficient and somewhat elegant. — , Nov 02 '10 at 05:04

Mehrdad Afshari · Accepted Answer · 2009-05-14T17:30:08.003

14

#include <iomanip>
using namespace std;
// ...
out << fixed << val;
// ...

You might also consider using setprecision to set the number of decimal digits:

out << fixed << setprecision(2) << val;

edited May 14 '09 at 17:30

answered May 14 '09 at 16:10

Mehrdad Afshari

score 8 · Answer 2 · edited Apr 09 '13 at 01:41

8

#include <iomanip>

std::string doubleToString(double val)
{
   std::ostringstream out;
   out << std::fixed << val;
   return out.str();
}

edited Apr 09 '13 at 01:41

scunliffe

answered May 14 '09 at 16:12

workmad3

score 2 · Answer 3 · answered May 14 '09 at 17:58

2

You can also set the minimum width and fill char with STL IO manipulators, like:

out.width( 9 );
out.fill( ' ' );

answered May 14 '09 at 17:58

Nikolai Fetissov

3 Answers3