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  • Types of character strings
  • Special case
  • Fixed string and ASCIIZ string
  • Processing fixed strings
  • Notes
  • Default value
  • Passing a character string as a parameter to a procedure
  • Using quotes in a character string
  • Comparing the different types of strings available in WINDEV and in WINDEV Mobile
WINDEV
WindowsLinuxUniversal Windows 10 AppJavaReports and QueriesUser code (UMC)
WEBDEV
WindowsLinuxPHPWEBDEV - Browser code
WINDEV Mobile
AndroidAndroid Widget iPhone/iPadIOS WidgetApple WatchMac CatalystUniversal Windows 10 App
Others
Stored procedures
Types of character strings
WLanguage proposes different types of character strings.
1. The most common types are as folllows:
  • Character
Character coded on 1, 2 or 4 bytes according to the management mode of character strings and the runtime platform.
  • In Windows:
    • in Ansi, a character is encoded on 1 byte,
    • in Unicode, a character is encoded on 2 bytes.
  • In Linux:
    • in Ansi, a character is encoded on 1 byte,
    • in Unicode, a character is encoded on 4 bytes.
  • In iOS, in Unicode, a character is coded on 4 bytes.
When a character is empty, its value corresponds to Charact(0).
  • Versions 17 and later
    Ansi string
    New in version 17
    Ansi string
    Ansi string
Variable-length string containing ANSI characters only.
This format is required to handle:
  • XML files
  • RTF files
  • PDF files
  • functions that use UTF8 format, etc.
  • Unicode string
Variable-length string containing UNICODE characters only.
  • String
Variable-length string.

The "string" type is specific to the WLanguage. With this type, there is no need to declare the length of the string. It can change when the variable is used.
  • Buffer
Binary memory area. Used to write a code that can be shared between WINDEV and WINDEV Mobile regarding the use of raw data. For more details, see the "Buffer" type.
2. Other types of character strings can also be used:
  • String on
Fixed-length string, ending with a binary 0 (as in C). The specified size is the maximum number of characters in the string.
This type of character string is used to create compatible WINDEV/WINDEV Mobile code when calling APIs from both platforms.
  • ASCIIZ string on
String ending with a binary 0 (as in C).
The length of an ASCIIZ string cannot exceed 2 GB. The length given to the ASCIIZ string must be equal to its current length plus 1 (for the binary zero).
  • Fixed string on
Fixed-length string.
A fixed-length string cannot exceed 2 GB. The character string is completed:
  • with 0 if the variable is not assigned yet.
  • with space characters if necessary if the variable is assigned (similar to the "string" type of Basic).
  • Pascal string on
String preceded by a byte that specifies the length (similar to Pascal). This byte is not accessible. For example string[1] represents the first character of the string and not its length.
The length of a Pascal string cannot exceed 255 characters. The length given to the Pascal string must be equal to the length of the string.
  • Unicode string on
Fixed-length string containing UNICODE characters only.
Remarks:
  • The "String on" type must be used to send input/output parameters to a Windows API.
  • All the advanced types (other than "String") are available for compatibility with the other programming languages (Turbo Pascal Windows, C, Visual Basic Windows, etc.) or to receive the result of a Windows API.
  • WINDEV Mobile and WINDEV do not propose the same types of character strings. For more details on the different types of character strings available, see the Notes section.
Special case
Reports and QueriesWindows

Fixed string and ASCIIZ string

  • When declaring an ASCIIZ string or a fixed string, the necessary memory is immediately allocated. Therefore, you should avoid using very large strings.
  • The fixed string is filled with space characters. The initialization and assignment of a large string (several hundreds of kB) may take quite a long time.
Windows

Processing fixed strings

The fixed strings are not available in Java. They are replaced with the String type at runtime.
However, Complete can be used on a String variable:
MyString is string
MyString = Complete("Test", 10)
// Equivalent to
// MyString is fixed string on 10 characters
// MyString = "Test"
Notes

Default value

  • A "String" or "String on" variable that is declared but not initialized corresponds to an empty string ("").
  • A "Buffer" variable that is declared but not initialized is empty.
  • A "Buffer on" variable that is declared but not initialized is filled with 0.

Passing a character string as a parameter to a procedure

A "String" variable can be passed as parameter to a procedure.
Caution: If the variable has a fixed length, you must remove spaces. For example:
MyString is string
MyString = "WINDEV is great"
// Delete spaces from MyString
MyString = NoSpace(MyString)
CountLetter(MyString)
// CountLetter is a procedure

Using quotes in a character string

To use the quote character in a character string, this character must be repeated twice.
For example:
MyString is string
MyString = "The ""General conditions"" option must be checked"
Info(MyString)
// Displays: The "General conditions" option must be checked
Reports and QueriesWindows

Comparing the different types of strings available in WINDEV and in WINDEV Mobile

WINDEV/WEBDEV
String format
WINDEV Mobile
String format
StringANSIUnicode
CharacterANSIUnicode
ASCIIZ string onANSI string of N charactersnot available
Fixed string onANSI string of N charactersnot available
Pascal string onANSI string of N charactersnot available
Unicode stringUnicodeUnicode
BufferBinaryBinary
String onANSI string of N charactersUnicode string of N characters
Unicode string onUnicode string of N charactersUnicode string of N characters
Buffer onBinary memo of N bytesBinary memo of N bytes
Related Examples:
Different types of strings Unit examples (WINDEV): Different types of strings
[ + ] Using the different types of strings available in WINDEV.
The specific features of each type are presented in details.
Types used:
- "Standard" string
- UNICODE string
- Fixed string
- Pascal String
- ASCIIZ String
- Buffer type
Minimum version required
  • Version 9
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