Language elements - JavaTech: An Introduction to Scientific and Technical Computing with Java - page 684

Table A.1.2 Reserved symbols in Java.

Symbol Description

Semi-colon indicates the end of a statement.

;

Parentheses are used in several places. They override the default precedence in an
expression that contains multiple operators.
They indicate a method and also a casting operator. They surround the logic test in an
if statement, e.g.

()

if (test) doSomething();

[] Array declaration and an array element specification.

{} Curly braces enclose the fields and methods of a class, the code for a method, the code

body for an if statement, a for loop statement, a synchronized block, and initial
values for an array declaration.

Indicates a single line comment.

//

Bracket a set of comments that can span more than one line.
The /** */ version is the same as /* */ except the double asterisks tells javadoc to
use the comments in its output.

/*. .*/
or
/**. .*/

Colon is used in switch statements and the conditional operator. Also, it is used in the
enhanced for-loop.

:

“xx „

Double quotes surround a string literal.

Single quotes surround a character literal.

` x'

+,-, etc

Operator symbols. See Appendix 2 for a listing of operators.

Used with annotation. (J2SE 5.0)

@

Indicates generics. (J2SE 5.0)

<>

Used with the Formatter class and printf() to specify output formats. (J2SE 5.0)

%

Used with the conditional operator:

?

x = boolean ? y: z;

As of Java 5.0, '?' acts also as a type wildcard in generics.

Notes:

identifiers (names of data, methods and classes) cannot begin with a number

whitespace (space, line return) is ignored in Java code

non-printing ASCII characters use backslash, e.g. ` \ t' = tab, ` \ n' = return.

Unicode character specified with ` \ u + 4 hex values ' , e.g. ` \ u03c0' = π .