Integer and floatingpoint literals
Literals or constants that represent numbers can be integer or floatingpoint.
Integer literals
An integer constant is a sequence of the digits 09, with an optional positive (+) or negative () sign preceding the digits.
Syntax
[ +   ] digit ...
Examples
Valid integers include the following:
23 555 +17
Floatingpoint literals
Floatingpoint literals (also referred to as decimal, numeric, or fractional literals) are sequences of digits that can include a decimal point, and optionally the exponent marker (e).
Syntax
[ +   ] digit ... [ . ] [ digit ...] [ e  E [ +   ] digit ... ]
Arguments
 e  E

e or E indicates that the number is specified in scientific notation.
Examples
Valid floatingpoint literals include the following:
3.14159 37. 2.0e19 2E19