ab1.23cd
n=7

Characters: a A
Decimals: 1977 650000 12 4
Preceding with blanks:       1977      -1977
Preceding with zeros: 0000001977 -000001977
Force sign: +1977 -1977  +1977  -1977
Force sign or space:  1977 -1977   1977  -1977
Sign overrides space: +1977 -1977  +1977  -1977
Some different radixes: 100 64 144 0x64 0144
floats: 3.14 +3e+00 3.141600E+00 00003.14
negative floats: -3.14 -3e+00 -3.141600E+00 -0003.14
Force sign or space:  3.14 -3.14   3.14  -3.14
Width trick:    10
A string %
Null string:  (null)
inf
INF
-inf
-INF
nan
NAN
       nan
nan       
       nan
nan       
       inf
-inf