C++ Floating point Display

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Possible Duplicate:
floating point precision

when I do cout<<8.0 .Its getting printed as 8.How to Print in the output console of c++ the entire zeros after decimal point like 8.00000000 I tried this cout<<setprecision(5)<<(double)8.0; still printing 8

@wallyk I saw that post ,evn tried ,but its printing as the part before decimal when there are only zeros after decimal — nightrider, Dec 06 '12 at 02:39
http://stackoverflow.com/questions/554063/how-do-i-print-a-double-value-with-full-precision-using-cout cout.precision(15); cout << 8.0; — Jonathan Vukovich-Tribouharet, Dec 06 '12 at 02:45
@JonathanTribouharet At first I thought the question was a duplicate of that one too, but I get "8" printed _unless_ I also use `fixed`. — Ray Toal, Dec 06 '12 at 02:49

score 2 · Accepted Answer · answered Dec 06 '12 at 02:46

2

Use the fixed manipulator

#include <iostream>
#include <iomanip>

using namespace std;

int main() {
    cout << fixed << setprecision(6) << (double)8 << "\n";
    return 0;
}

http://ideone.com/ShcNIc

answered Dec 06 '12 at 02:46

Ray Toal

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Thanks Problem solved.Juz one more thing is there a way to determine the number of values after decimal.Because setprecision also takes in account the mantissa – nightrider Dec 06 '12 at 02:54
Actually it doesn't, if I understand your question correctly. See http://www.cplusplus.com/reference/iomanip/setprecision/ -- it says "In both the fixed and scientific notations, the precision field specifies exactly how many digits to display after the decimal point, even if this includes trailing decimal zeros. The number of digits before the decimal point does not matter in this case." – Ray Toal Dec 06 '12 at 04:17

score 0 · Answer 2 · edited May 23 '17 at 10:24

0

See How do I print a double value with full precision using cout?

cout.precision(15);
cout << fixed << 8.0;

edited May 23 '17 at 10:24

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answered Dec 06 '12 at 02:50

Jonathan Vukovich-Tribouharet

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C++ Floating point Display

2 Answers2