Java Language Literals Hexadecimal, Octal and Binary literals


A hexadecimal number is a value in base-16. There are 16 digits, 0-9 and the letters A-F (case does not matter). A-F represent 10-16.

An octal number is a value in base-8, and uses the digits 0-7.

A binary number is a value in base-2, and uses the digits 0 and 1.

All of these numbers result in the same value, 110:

int dec = 110;            // no prefix   --> decimal literal
int bin = 0b1101110;      // '0b' prefix --> binary literal
int oct = 0156;           // '0' prefix  --> octal literal
int hex = 0x6E;           // '0x' prefix --> hexadecimal literal

Note that binary literal syntax was introduced in Java 7.

The octal literal can easily be a trap for semantic errors. If you define a leading '0' to your decimal literals you will get the wrong value:

int a = 0100;        // Instead of 100, a == 64