0x00ff

0x00FF is a hexadecimal integer literal commonly used in programming and digital electronics. The value it represents is 255 in decimal. The notation indicates a 16-bit-style composition with a high byte of 0x00 and a low byte of 0xFF, corresponding to the binary pattern 00000000 11111111.

In many programming languages, 0x00FF is treated as a constant with the value 255. The exact type (such as int or unsigned int) depends on the language and platform. When working with narrower types, 0x00FF can be cast to an 8-bit unsigned value of 0xFF. Leading zeros in hexadecimal literals are often used to convey width or alignment, but they do not change the value.

Common uses for 0x00FF include bit masking and low-level data handling. As a mask, value & 0x00FF clears all but the least significant byte, leaving the lower 8 bits unchanged. In hardware and embedded systems, 0x00FF is sometimes employed to select or examine the lower byte of a 16-bit register. Endianness affects how 0x00FF is stored in memory: in big-endian systems the byte order is 00 followed by FF, while in little-endian systems it is stored as FF followed by 00.

Related concepts include hexadecimal notation (prefix 0x), other common hex constants such as 0x00FF00, and the equivalence between 0x00FF and 0xFF in value, though width and interpretation can differ by context.