String (Variable type)

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Default value
Adaptation to ANSI/Unicode
ANSI string
Unicode string
Different types of strings
extension attribute
Notes

WINDEV

WEBDEV

WINDEV Mobile

Others

See also

String (Variable type)

In french: String

The String type is used to manipulate strings. This type of variable is a string with a size defined dynamically.

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.

The String type supports null values. For more details, see Allowing nullable types.

Remarks:

The Buffer type is also available. This type corresponds to a binary memory area. It allows you to write code for raw data manipulation, usable in both WINDEV and WINDEV Mobile.
For a variable of type String, TypeVar returns the wlString constant (value: 16).
A String variable can contain a single-line string, a multiline string or a dynamically built string including variables. For more details, see String literals.

Example

Prénom is string
Prénom = "Florence"

Syntax

Declaring and initializing a "String" variable Hide the details

<Nom de la variable> is an [ANSI] [Unicode] string = <Valeur>
OR

<Nom de la variable> is an [ANSI] [Unicode] string
<Variable name> = <Value>

<Variable name>:

Name of the variable to declare. When several variables of the same type are declared and initialized on the same line, only the last variable is initialized.

<ANSI>: Optional

Indicates that the string is an ANSI string. If this parameter is not specified, the string format will adapt to the format defined for the platform. For more details, see Adaptation to ANSI/Unicode.

<Unicode>: Optional

Indicates that the string is a Unicode character string. If this parameter is not specified, the string format will adapt to the format defined for the platform. For more details, see Adaptation to ANSI/Unicode.

<Value>:

Value given to the variable.

Remarks

Default value

A declared and uninitialized "String" variable corresponds to an empty string ("").

Adaptation to ANSI/Unicode

If the current configuration uses ANSI strings at runtime, the String variables will be ANSI strings (default behavior).
If the current configuration uses Unicode strings at runtime, variables of type String will be Unicode strings.
This type of string is in Unicode format.

Reminder: To modify string management in the current configuration:

Open the project description window. To do so, go to the "Project" tab, "Project" group, and click "Description".
On the "Project" tab, click "Configuration description".
In the window that appears, go to the "Unicode" tab and select the desired mode.

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

Dynamic size string containing only Unicode characters.

In a configuration using ANSI strings at runtime, this type of string can be returned by the AnsiToUnicode function or by one of the Unicode string manipulation functions.
For more details, see Unicode management.

This string type is used by default if the current configuration uses Unicode strings at runtime.

This type of character string is not supported. It is replaced with the String type.

This type of character string is not supported.

Different types of strings

WLanguage also offers the following string types:

Character,
ANSI string,
Unicode string.
String of,
ASCIIZ string of,
Fixed string of (kept for compatibility),
Pascal string of (kept for compatibility),
Unicode string on.

<undetectable> extension attribute

The <undetectable> extension attribute obfuscates the value of a string stored in memory (for example, in a memory dump file).
By default, (if the <undetectable> extension attribute is not specified), all characters assigned to a String variable are visible in a memory dump file. These characters are visible among all the information present in the dump: it is not possible to identify the beginning and end of the string, and there is no way of identifying what the string corresponds to..

The <undetectable> attribute obfuscates the value stored in memory. The value of the string cannot be determined based on the visible characters in the dump file.

This extension attribute is particularly useful to store a username or password in memory, to pass a password to HPass, or to connect to a database.

Example:

MaChaîneMémoire is string <undetectable>
MaChaîneMémoire = "MotDePasse"

Remarks:

Using the <undetectable> extension attribute can slow down the application. It should only be used on strings that require that attribute.
The <undetectable> extension attribute is not available for fixed-length strings.

Notes

A "String" variable is limited to 2 GB.. Indirectly, functions manipulating character strings are affected by this limit.

Related Examples:

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