Java Data Type Tutorial - Java Underscores Numeric Literals

We can use underscores between two digits in numeric literals.

For example, an int literal 2014 can be written as 2_014, 20_14, 201_4.

The use of underscores is allowed in octal, hexadecimal, and binary formats.

int underscores in big numbers makes them easier to read.

The following examples show the valid uses of underscores in numeric literals:

int x1  = 2_014;     // Underscore in  deciaml format
int x2  = 2___014;   // Multiple consecutive underscores 
int x3  = 02_014;    // Underscore in  octal literal
int x4  = 0b0111_1011_0001;  // Underscore in binary literal
int x5  = 0x7_B_1;           // Underscores in hexadecimal literal 
byte b1 = 1_2_7;             // Underscores in decimal format 
double d1 = 2_014.01_11;     // Underscores in double literal

Underscores are allowed in numeric literals only between digits.