Java built-in data types

The amount of constants that will not be modified while the program is running.

Use the final keyword in Java to decorate a constant declaration in a way that is similar to a variable

Finaldouble PI = 3.1415927;

Although constant names can also be lowercase, uppercase letters are usually used to denote constants for easy identification.

Literals can be assigned to variables of any built-in type. For example

byte a = 68; char a = ' a '

byte, int, long, and short can all be represented in decimal, 16-binary, and 8-binary ways.

When a constant is used, the prefix 0 represents 8 binary and the prefix 0x represents 16 binary. For example

intdecimal=100; int octal = 0144; int Hexa =0x64;

As in other languages, a string constant of Java is also a sequence of characters that is contained between two quotation marks. The following is an example of a string literal

"Hello World" "Two\nlines" "\" This is in Quotes\ ""

Both string constants and character constants can contain any Unicode characters. For example

char a = ' \u0001 '; String a = "\u0001";

The Java language supports some special sequences of escape characters.

symbols	character meaning
\ n	Line Break (0x0a)
\ r	Enter (0x0d)
\f	Page Break (0x0c)
\b	BACKSPACE (0x08)
\s	Space (0x20)
\ t	Tabs
\"	Double quotes
\‘	Single quotation marks
\\	Back slash
\ddd	octal character (DDD)
\uxxxx	16 Binary Unicode characters (xxxx)

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Java built-in data types