UTF16kodeenheter

UTF16kodeenheter refers to the fundamental units used in the UTF-16 encoding scheme for representing Unicode characters. UTF-16 is a variable-length character encoding capable of encoding all 1,112,064 valid code points in the Unicode standard. The basic unit in UTF-16 is a 16-bit word, hence the name.

Characters within the Basic Multilingual Plane (BMP), which covers the first 65,536 Unicode code points (U+0000 to U+FFFF), are represented by a single 16-bit UTF-16 code unit. This means these characters are encoded using exactly 16 bits.

For characters outside the BMP, known as supplementary characters, UTF-16 employs a mechanism called surrogate pairs. A surrogate pair consists of two 16-bit UTF-16 code units. The first code unit is a high surrogate, and the second is a low surrogate. These two units are specifically designed to represent a single character that falls outside the BMP. This allows UTF-16 to represent the entire range of Unicode characters using either one or two 16-bit units. The choice of representing characters with one or two units makes UTF-16 efficient for languages that predominantly use characters within the BMP, while still supporting characters from other planes.