Floating Point Literals

Floating point literals may be expressed in a variety of formats to simplify the task of expressing different ranges of values.


  • Cannot start with 0 unless the 0 is followed by a decimal point.
  • Can use 'e' notation to express exponential values (ke±n represents k·10±n).
  • May include a decimal point (should be included when not using 'e' notation).
  • Cannot include commas or spaces.
  • Must use only the digits zero-nine.
  • May be preceded by a minus sign "-".

Examples of Valid Floating Point Literals

2.56e-5 10.4378 48e8 0.5 10f 10.2f

The 'f' in the last two examples is a literal qualifier, described on the next page. It forces the compiler to treat it as a float, which would otherwise be treated as something else:

  • 10 would be treated as an int
  • 10.2 would be treated as a double

We'll see why this is important in the section on operators.

Examples of Invalid Floating Point Literals

0x5Ae-2 02.41 F2.33 0x2.A
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