Java Quick Reference - Language Fundamentals

Language Fundamentals

Operators and Assignments

Flow Control and Exceptions

Declarations and Access Control

Garbage Collection

Overloading and Overriding

Threads

The java.lang Package

The java.util Package

The java.awt Package

The java.io Package

References

Miscellaneous Notes

Tips & Traps

Mock Exams

Language Fundamentals - Character Literals

the char type represents 16-bit Unicode characters
Unicode is a superset of the ASCII character set which allows non-English language characters
any Unicode character can be written as a literal using the Escape character (backslash \) and it's hexadecimal representation
```
        '\udddd'    // where 'dddd' = hex digit (0 - F)
```

single characters are represented within single quotes

    'a'         // char literal
    '9'         // char literal

there are three exceptions that require the use of the Escape character

    single quote    ' \' '      displays as '
    double quote    ' \" '      displays as "
    backslash       ' \\ '      displays as \

there are certain special characters which can be represented by escape sequences

Esc Char	Unicode Char	Definition
\n	\u000A	newline
\t	\u0009	tab
\b	\u0008	backspace
\r	\u000D	return
\f	\u000C	form feed
\ddd		octal value

Octal character constants can have three digits or less (\000 through \377)

!!! Warning !!!

The compiler translates Unicode characters at the beginning of the compile cycle.

Using the Unicode escape characters \u000A for newline and \u000D for return in a String or comment produces a compile-error as they are interpreted, literally, as 'end-of-line'.

Always use the special characters '\n' or '\r'

Traps

String literal "c" assigned to char type

Source	Package	Import	Class	Interface	Constructors
Methods	main()	Identifiers	Keywords	Defaults	Arrays
Primitives	# Literals	char Literal	String Literals	Class Literals