why double stores no upto 3 decimal places ?

[new_developer]

Hi everyone,

Please check my code below and tell me that why double stores number upto 3 decimal places ?

#include <iostream>

using namespace std;

int main()
{
    double dNo;
    dNo = 363.430965;

    cout<<"double no : " <<dNo <<endl;
    //cout only outputs dNo value upto 
    //3 decimal places

    return 0;
}

Actually i working on assignment in which i need to get number upto different decimal places say 3, 4 etc. But in above case it only store that number upto 3 decimal places and also rounds it off.

How can i store decimal number upto 5, 6 or greater decimal places in double ???

Kindly give me the solution and explain this issue in detail. Thanks !

Regards

[rproffitt]

So, yes. There are only so many decimal digits in various floating point reprentations.
http://stackoverflow.com/questions/13931062/double-10-decimal-point-precision kicks it around a little so why not use the type that fits your needs?

[new_developer]

Thanks for shairing that link :
http://stackoverflow.com/questions/13931062/double-10-decimal-point-precision

But it provides solution in C i need in C++ !

[rproffitt]

From what I did in C and C++, the data types are the same. Since you only get so many decimal digits in each floating point representations you choose which fits your needs.

If you feel you need formatted output, there's still printf() and other ideas at http://stackoverflow.com/questions/15106102/how-to-use-c-stdostream-with-printf-like-formatting