Again, the number of digits following the decimal point is controlled by the precision. The exponent always contains at least two digits. Trailing zeros are removed from the fractional portion of the result and a decimal-point character appears only if it is followed by a digit. Normally the result is right-justified. For these conversions, the default precision is 6 .
Significant digits are the first digit before the decimal point, and all the digits after it.
If the value being printed cannot be expressed accurately in the specified number of digits, the value is rounded to the nearest number that fits. Without a type modifier, the floating-point conversions use an argument of type double . Here are some examples showing how numbers print using the various floating-point conversions.