3.10.4

Character Literals

LEXICAL STRUCTURE

3.10.4   Character Literals

A

character literal

 is expressed as a character or an escape sequence, enclosed in

ASCII single quotes. (The single quote, or apostrophe, character is

\u0027

.)

A character literal is always of type

char

.

CharacterLiteral:

SingleCharacter

EscapeSequence

SingleCharacter:

InputCharacter

 but not

 or

\

The escape sequences are described in  3.10.6.

As specified in  3.4, the characters

CR

 and

LF

 are never an

InputCharacter

;

they are recognized as constituting a

LineTerminator

.

It is a compile time error for the character following the

SingleCharacter

 or

EscapeSequence

 to be other than a

.

It is a compile time error for a line terminator to appear after the opening

and before the closing

.

The following are examples of

char

 literals:

 a 

 % 

 \t 

 \\ 

 \  

 \u03a9 

 \uFFFF 

 \177 

Because Unicode escapes are processed very early, it is not correct to write

 \u000a 

 for a character literal whose value is linefeed (

LF

); the Unicode escape

\u000a

 is transformed into an actual linefeed in translation step 1 ( 3.3) and the

linefeed becomes a

LineTerminator

 in step 2 ( 3.4), and so the character literal is

not valid in step 3. Instead, one should use the escape sequence

 \n 

 ( 3.10.6).

Similarly, it is not correct to write

 \u000d 

 for a character literal whose value is

carriage return (

CR

). Instead, use

 \r 

.

In C and C++, a character literal may contain representations of more than

one character, but the value of such a character literal is implementation defined.

In Java, a character literal always represents exactly one character.

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