The basic concept of any programming language is variable. A variable is a container in which we can store any data, for example, strings or numbers.
Each variable must have a name, the latter
can consist of Latin letters, numbers,
symbols $
and underscores. The first
character of the variable name must not be a digit.
Variable names examples: str
, my_str
,
myStr
, a1
, $
,
$a
, $$a
.