Data type and format control characters

• Fixed length decimal, float is 4 bytes, 8 bytes double
  % f decimal output type float
  % lf decimal output of the first two types of double default save six decimal places, insufficient bits 0s, over six truncated
  % e output exponentially decimal, the output e in lowercase
  % E output decimal exponentially, the output of E uppercase
  % le output decimal exponentially, the output e in lowercase
  % lE output decimal exponentially, the resulting output E capital
  % g is a more intelligent representation, using fewer characters

• The default type numbers:
  integer default int, decimal default double.