Define the following terms:

Question

a) Code value.
b) Surrogates.
c) Unicode Standard.
d) UTF-8.
e) UTF-16.
f) UTF-32.

Answer 1

a) Code value.
ANS: A code value is a combination of bits that represents an encoded character. The notation for a code value is U+yyyy, where U+ indicates that the encoding conforms to the Unicode Standard. The yyyy represents the hexadecimal number.
b) Surrogates.
ANS: Surrogates are extension mechanisms that allow the Unicode Standard to incorporate additional characters. Surrogates are 16-bit integers in the range D800 through DFFF that are used solely for the purpose of “escaping” into higher numbered characters. Approximately one million characters can be expressed in this manner. Surrogates are used with the UTF-16 encoding form.
c) Unicode Standard.
ANS: The Unicode Standard is an encoding standard that facilitates the uniform production and distribution of software. It outlines a specification to produce the consistent encoding of characters and symbols. Characters and symbols are assigned a unique four-digit hexadecimal code value that differentiates them from other characters.
d) UTF-8.
ANS: UTF-8, a variable-width encoding form, requires one to four bytes to express each Unicode character. UTF-8 data consists of 8-bit bytes (sequences of one, two, three or four bytes, depending on the character being encoded) and are well suited for ASCII-based systems when there is a predominance of one-byte characters. ASCII represents characters as one byte.
e) UTF-16.
ANS: The variable-width UTF-16 encoding form expresses Unicode characters in units of 16 bits. Most characters of Unicode are expressed in a single 16-bit unit. However, characters with values above FFFF hexadecimal are expressed with an ordered
pair of 16-bit units called surrogates.
f) UTF-32.
ANS: UTF-32 is a 32-bit, fixed-width encoding form that usually requires twice as
much memory as do UTF-16 encoded characters. The major advantage of the UTF-
32 encoding form is that it uniformly expresses all characters, so it is easy to handle
in arrays.