printf ("floats: %4.2f %+.0e %E \n", 3.1416, 3.1416, 3.1416);
floats: 3.14 +3e+000 3.141600E+000
printf ("floats: %4.2f %+.0e %E \n", 3.1416, 3.1416, 3.1416);
floats: 3.14 +3e+000 3.141600E+000
c char conversion float precision print printf string
376Variable length of accuracy of float in NSString 313Swimming