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
Usage: BigInt literals like 0xFFn are used when precise integer arithmetic is needed beyond the safe range
Syntax and compatibility: BigInt literals with a trailing n were introduced in ES2020, and hexadecimal BigInt
Examples and notes: You can combine 0xFFn with other BigInt literals, for instance 0xFFn + 0x01n equals