Variables are examples of identifiers. Identifiers are names given to identify something. There are some rules you have to follow for naming identifiers:
The first character of the identifier must be a letter of the alphabet (upper or lowercase) or an underscore ('_').
The rest of the identifier name can consist of letters (upper or lowercase), underscores ('_') or digits (0-9).
Identifier names are case-sensitive. For example, myname
and myName
are not the
same. Note the lowercase n
in the former and the
uppercase N
in te latter.
Examples of valid identifier names are
i
, __my_name
, name_23
and a1b2_c3
.
Examples of invalid identifier names are
2things
, this is spaced out
and my-name
.