Perl : we should know scalar values

1. Perl supports three kinds of scalar values:
integers,
floating-point numbers
characterstrings.

2.Integers can be in three notations:
standard (decimal) notation,
octal notation, and
hexadecimal

Octal notation is indicated by a leading 0,
hexadecimal notation is indicated by a leading 0x.
Integers are stored as floating-point values and can be as long as the machine's
floating-point precision (usually 16 digits or so).

3. Floating-point numbers can consist of a string of digits that contain a decimal point and an
optional exponent.