OpenOffice.org BASIC Guide.pdf - OpenOffice.org wiki

Strings 10
Strings
Strings, together with numbers, form the most important basic types of OpenOffice.org
Basic. A string consists of a sequence of consecutive individual characters. The computer
saves the strings internally as a sequence of numbers where each number represents one
specific character.
From a Set of ASCII Characters to Unicode
Character sets match characters in a string with a corresponding code (numbers and
characters) in a table that describes how the computer is to display the string.
The ASCII Character Set
The ASCII character set is a set of codes that represent numbers, characters, and special
symbols by one byte. The 0 to 127 ASCII codes correspond to the alphabet and to common
symbols (such as periods, parentheses, and commas), as well as some special screen and
printer control codes. The ASCII character set is commonly used as a standard format for
transferring text data between computers.
However, this character set does not include a range of special characters used in Europe,
such as â, ä, and î, as well as other character formats, such as the Cyrillic alphabet.
The ANSI Character Set
Microsoft based its Windows product on the American National Standards Institute (ANSI)
character set, which was gradually extended to include characters that are missing from
the ASCII character set.
Code Pages
The ISO 8859 character sets provide an international standard. The first 128 characters of
the ISO character set correspond to the ASCII character set. The ISO standard introduces
new character sets (code pages) so that more languages can be correctly displayed.
However, as a result, the same character value can represent different characters in
different languages.
Unicode
Unicode increases the length of a character to four bytes and combines different character
sets to create a standard to depict as many of the world's languages as possible. Version 2.0
of Unicode is now supported by many programs — including OpenOffice.org and
OpenOffice.org Basic.
String Variables
OpenOffice.org Basic saves strings as string variables in Unicode. A string variable can
store up to 65535 characters. Internally, OpenOffice.org Basic saves the associated
Unicode value for every character. The working memory needed for a string variable
depends on the length of the string.
Example declaration of a string variable: