String Variables

 < EN | The OpenOffice.org Documentation Project | OpenOffice.org BASIC Programming Guide

BASIC Guide

{{{parttitle}}}

[[{{{PrevPart}}}|← Previous Section ]]

[[{{{NextPart}}}|Next Section →]]

• The Language of OpenOffice.org Basic

• Overview of a Basic Program
• Working With Variables
• Strings
• Numbers
• Boolean Values
• Date and Time
• Arrays
• Scope and Life Span of Variables
• Constants
• Operators
• Branching
• Loops
• Procedures and Functions
• Error Handling
• Other Instructions

• Runtime Library

• Conversion Functions
• Strings
• Date and Time
• Files and Directories
• Message and Input Boxes
• Other Functions

• Introduction to the API

• Universal Network Objects (UNO)
• Properties and Methods
• Modules, Services and Interfaces
• Tools for Working with UNO
• Overview of Central Interfaces

• Working with Documents

• The StarDesktop
• Styles and Templates

• Text Documents

• The Structure of Text Documents
• Editing Text Documents
• More than Just Text

• Spreadsheet Documents

• The Structure of Spreadsheets
  • Rows and Columns
  • Cells and Ranges
  • Formatting Spreadsheet Documents
• Editing Spreadsheet Documents

• Drawings and Presentations

• The Structure of Drawings
• Editing Drawing Objects
• Presentations

• Charts (Diagrams)

• Using Charts in Spreadsheets
• The Structure of Charts
• Chart Types

• Databases

• SQL: a Query Language
• Types of Database Access
• Data Sources
• Database Access

• Dialogs

• Working With Dialogs
• Properties
• Events
• Dialog Control Elements

• Forms

• Working With Forms
• Control Element Forms
• Database Forms

← Previous Page

Next Page →

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:

Dim Variable As String

You can also write this declaration as:

Dim Variable$

VBA : When porting VBA applications, ensure that the maximum allowed string length in OpenOffice.org Basic is observed (65535 characters).

Specification of Explicit Strings

To assign an explicit string to a string variable, enclose the string in quotation marks (").

Dim MyString As String
MyString = " This is a test"

To split a string across two lines of code, add an ampersand sign (the concatenation operator) and the underscore continuation character at the end of the first line:

Dim MyString As String
MyString =   "This string is so long that it " & _
             "has been split over two lines."

To include a quotation mark (") in a string, enter it twice at the relevant point:

Dim MyString As String
MyString = "a ""-quotation mark."    ' produces a "-quotation mark

Content on this page is licensed under the Public Documentation License (PDL).