Primitive types & literals

The eight built-in value types and how to write their literals.

Java's eight primitives

Most values in Java are either a primitive (a raw value) or a reference (a pointer to an object). There are exactly eight primitives:

Type	Size	Holds	Example
`boolean`	—	true/false	`true`
`byte`	8-bit	small int	`42`
`short`	16-bit	int	`1000`
`int`	32-bit	int (default)	`100000`
`long`	64-bit	big int	`9_000_000_000L`
`float`	32-bit	decimal	`3.14f`
`double`	64-bit	decimal (default)	`3.14`
`char`	16-bit	one character	`'A'`

Key literal rules: a whole number is an int unless suffixed L for long; a decimal is a double unless suffixed f for float. You can group digits with underscores for readability (1_000_000), and write other bases: 0x1F (hex), 0b1010 (binary), 0777 (octal). A char is a single character in single quotes — "A" is a String, 'A' is a char.