u8

u8 is an unsigned 8-bit integer type used in several programming languages to represent a single byte. In languages such as Rust and Zig, the type is named u8; in C-family languages the closest equivalent is uint8_t and it is commonly referred to simply as a byte.

It occupies one byte (8 bits) of memory, and its values range from 0 to 255. Because it represents a byte, endianness is not meaningful for individual u8 values, though it matters when assembling or parsing multi-byte integers or bitstreams.

Common uses include representing raw binary data, byte buffers, and encoded text units such as UTF-8 code units or ASCII codes. It is also employed for flags and small counters where a modest range is sufficient.

In Rust, u8 is a primitive numeric type that supports standard operations. Arithmetic on u8 follows modulo 256 semantics; overflow can wrap around unless you use checked, overflowing, or saturating methods. Values can be stored in arrays, slices (&[u8]), and vectors (Vec<u8>). Converting strings to bytes is often done via as_bytes() or into().

Other languages with similar types include Zig (u8) and C (uint8_t). These are used for interoperation with binary formats, network protocols, and hardware interfaces where precise control over byte-sized data is required.

See also: Byte, unsigned integer, uint8_t.