0xFFn

0xFFn is a BigInt literal used in JavaScript to denote an integer value written in hexadecimal notation. The 0x prefix signals hexadecimal, FF is the hexadecimal digits for 255, and the trailing n marks the value as a BigInt type rather than a standard Number.

Value and notation: 0xFFn evaluates to the BigInt 255n. It is an exact integer value, unlike floating-point numbers.

Usage: BigInt literals like 0xFFn are used when precise integer arithmetic is needed beyond the safe range of Number or when exact integer operations are desired. They support operators such as +, -, *, /, %, left and right shifts, and comparisons with other BigInts. Division yields a BigInt result truncated toward zero. BigInt cannot be mixed directly with Number without explicit conversion.

Syntax and compatibility: BigInt literals with a trailing n were introduced in ES2020, and hexadecimal BigInt literals such as 0xFFn are supported in all modern JavaScript engines. Node.js 10+ and modern browsers support them.

Examples and notes: You can combine 0xFFn with other BigInt literals, for instance 0xFFn + 0x01n equals 0x100n. To display the value as a decimal string, convert to Number or use 0xFFn.toString(), which returns '255'. When interacting with APIs that expect Number, convert explicitly with Number(0xFFn).