iex> :io.format("Pi is approximately given by:~10.3f~n", [:math.pi])
Pi is approximately given by:     3.142
:ok
iex> to_string :io_lib.format("Pi is approximately given by:~10.3f~n", [:math.pi])
"Pi is approximately given by:     3.142\n"

也要注意Erlang的格式函數(shù)對于處理Unicode有特殊的要求.