See the following list of the basic
source character sets that are available at both compile time and
run time:
- The uppercase and lowercase letters of the English alphabet:
a b c d e f g h i j k l m n o p q r s t u v w x y z
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
- The decimal digits:
0 1 2 3 4 5 6 7 8 9
- The following graphic characters:
! " # % & ' ( ) * + , - . / : ; <
= > ? [ \ ] _ { } ~
- The caret (‸) character in ASCII (bitwise exclusive OR symbol).
- The split vertical bar character
in ASCII.
- The space character
- The control characters representing new-line, horizontal tab,
vertical tab, form feed, end of string (NULL character), alert, backspace,
and carriage return.
Depending on the compiler option, other specialized identifiers,
such as the dollar sign ($) or characters in national character sets,
may be allowed to appear in an identifier.