C++: outputting a long double type variable gives only 6 digits?

Heres the program:





#include %26lt;iostream%26gt;


using namespace std;





int main()


{


long double pi=4.00;


bool op=false;





for (long double n=3.00;n%26lt;1000000.00;n+=2.00)


{


if (op==true)


{pi+=4.00/n; op=false;cout %26lt;%26lt; pi %26lt;%26lt; endl;}


else


{pi-=4.00/n; op=true; cout %26lt;%26lt; pi %26lt;%26lt; endl;}


}


system ("PAUSE");


return 0;


}








it returns more and more accurate approximations of pi, but it only returns 6 digits, doesnt long double have a precision of 19 digits??





i need it to output more digits after the decimal

C++: outputting a long double type variable gives only 6 digits?
Use iomanip.h header file and use std::setprecision(x), where x is the number of digits.





For example:


std::cout %26lt;%26lt; "Value is " %26lt;%26lt; std::setprecision(19) %26lt;%26lt; x %26lt;%26lt; std::endl;
Reply:Include %26lt;iomanip.h%26gt; and set the flags/precision. For example, this will display 8 digits and set the width to 20 places. also right justifies it.





cout %26lt;%26lt;setiosflags(ios::right)


%26lt;%26lt; setprecision(8)


%26lt;%26lt; setw(20)


%26lt;%26lt; myValue


%26lt;%26lt; resetiosflags(ios::right)


%26lt;%26lt; endl;
Reply:Sure, long double will have more. cout has a default precision of 6 only, and so only 6 is displayed.





Want more? Change it using the iomanip flags.