u16

u16 is a common shorthand for a 16-bit unsigned integer type used in many programming languages and data formats. It represents integer values in the range 0 to 65535 and occupies two bytes of memory. The actual byte order in memory depends on the system’s endianness, which is important when encoding values for binary protocols or file formats.

In programming languages, a u16 type appears under different names. In C and C++, the fixed-width type is uint16_t from stdint.h. In Rust, the primitive type is called u16. In Go, the equivalent type is uint16. In Python, fixed-size 16-bit integers can be handled via modules such as struct, array, or numpy, though Python’s built-in int is arbitrary-precision.

Arithmetic on u16 is typically modulo 2^16, so operations can wrap around on overflow in languages that use fixed-size integers. Some languages offer checked arithmetic options to detect overflow. Because of the limited range, u16 is suitable for compact counters or indexes when the upper bound does not exceed 65535, and it is often used in large arrays or memory-constrained contexts.

Common uses include representing numeric values in network protocols, file formats, and embedded systems. It is also used for color representations in certain 16-bit color formats (for example, 5-6-5). When sending u16 values over networks, converting to network byte order (big-endian) with appropriate utilities (such as htons/ntohs or language-specific equivalents) is essential for cross-platform compatibility.

See also u8, u32, fixed-width integers, endianness, and binary serialization.