LEXICAL STRUCTURE

Identifiers

3.8

CharactersInLine:

InputCharacter

CharactersInLine InputCharacter

These productions imply all of the following properties:

Comments do not nest.

/*

 and

*/

 have no special meaning in comments that begin with

//

.

//

 has no special meaning in comments that begin with

/*

 or

/**

.

As a result, the text:

/* this comment /* // /** ends here: */

is a single complete comment.

The lexical grammar implies that comments do not occur within character lit 

erals ( 3.10.4) or string literals ( 3.10.5).

Note that

/**/

 is considered to be a documentation comment, while

/* */

(with a space between the asterisks) is a traditional comment.

3.8   Identifiers

An

identifier

 is an unlimited length sequence of

Java letters

 and

Java digits

, the

first of which must be a Java letter. An identifier cannot have the same spelling

(Unicode character sequence) as a keyword ( 3.9), Boolean literal ( 3.10.3), or

the null literal ( 3.10.7).

Identifier:

IdentifierChars

 but not a

Keyword

 or

BooleanLiteral

 or

NullLiteral

IdentifierChars:

JavaLetter

IdentifierChars JavaLetterOrDigit

JavaLetter:

any Unicode character that is a Java letter (see below)

JavaLetterOrDigit:

any Unicode character that is a Java letter or digit (see below)

Letters and digits may be drawn from the entire Unicode character set, which

supports most writing scripts in use in the world today, including the large sets for

Chinese, Japanese, and Korean. This allows Java programmers to use identifiers in

their programs that are written in their native languages.

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