When doubles are printed, why do only 6 digits show on the output?

Question

just curious since I thought doubles could hold large values, but show only 6 by default
eg. double number = 1.231231;
cout << number;

[output:]
1.23123 //missing the last digit

Answer 1

6 digits of accuracy is standard for stream formatting in C++. Standard library includes many manipulators to control formatting, including setprecision that changes number of decimals printed:

http://www.cplusplus.com/reference/library/manipulators/

Answer 2

But doesn't set precision only set values after the decimal point? What if I just wanted the default formatting to be 10 digits and not 10 decimal spaces?

Answer 3

You may also use:

cout.setf(ios::fixed);
//To ensure that numbers are printed only in fixed notation, not as 10^ something...

cout.precision(10);
//Sets precision after decimal point...

cout<<number;
//outputs 1.2312310000

//Changes default precision...

Answer 4

Thanks for the info! Is there a way to change the default formatting of digits of accuracy if I wanted to set it to 10 digits instead of 6?

Answer 5

try setwidth

Answer 6

Yes, as I mentioned use setprecision:

cout << setprecision(10) << number;

Answer 7

that is interesting, Yes a double should be able to hold that value. It just might be something to do with the sololearn compiler. Try it on code::blocks and see if it does the same.