Literals

Use integer literals to specify an integer value in decimal, octal, or hex notation of the primitive types int, long, float, or double. Use the following single letter designations to specify the primitive type: l or L for long, f or F for float, and d or D for double. If not specified, the type defaults to int. Use 0 as a prefix to specify an integer literal as octal, and use 0x or 0X as a prefix to specify an integer literal as hex.

Grammar

INTEGER: '-'? ( '0' | [1-9] [0-9]* ) [lLfFdD]?;
OCTAL:   '-'? '0' [0-7]+ [lL]?;
HEX:     '-'? '0' [xX] [0-9a-fA-F]+ [lL]?;

Examples

Integer literals.

0     
0D    
1234L 
-90f  
-022  
0xF2A 

Use floating point literals to specify a floating point value of the primitive types float or double. Use the following single letter designations to specify the primitive type: f or F for float and d or D for double. If not specified, the type defaults to double.

Grammar

DECIMAL: '-'? ( '0' | [1-9] [0-9]* ) (DOT [0-9]+)? EXPONENT? [fFdD]?;
EXPONENT: ( [eE] [+\-]? [0-9]+ );

Examples

Floating point literals.

0.0      
1E6      
0.977777 
-126.34  
89.9F    

Use string literals to specify string values of the String type with either single-quotes or double-quotes. Use a \" token to include a double-quote as part of a double-quoted string literal. Use a \' token to include a single-quote as part of a single-quoted string literal. Use a \\ token to include a backslash as part of any string literal.

Grammar

STRING: ( '"'  ( '\\"'  | '\\\\' | ~[\\"] )*? '"'  )
      | ( '\'' ( '\\\'' | '\\\\' | ~[\\'] )*? '\'' );

Examples

String literals using single-quotes.

'single-quoted string literal'
'\'single-quoted string with escaped single-quotes\' and backslash \\'
'single-quoted string with non-escaped "double-quotes"'

String literals using double-quotes.

"double-quoted string literal"
"\"double-quoted string with escaped double-quotes\" and backslash: \\"
"double-quoted string with non-escaped 'single-quotes'"

Use the casting operator to convert string literals or String values into char values. String values converted into char values must be exactly one character in length or an error will occur.

Examples

Casting string literals into char values.

(char)"C"
(char)'c'

Casting a String value into a char value.

String s = "s";
char c = (char)s;