Numerical constants may be written in either decimal or hexadecimal form.

Decimal constants consist of one or more decimal digits. Decimal constants may optionally include a decimal point along with one or more decimal digits following the decimal point. Hexadecimal constants start with 0x or 0X followed by one or more hexadecimal digits.

x = 10;  // set x to 10
x = 0x10; // set x to 16 (10 hex)
f = 10.5; // set f to 10.5