Global and local variable

WINDEV, WEBDEV AND WINDEV MOBILE
ONLINE HELP

Version:

Home | Sign in | English

Overview
Global variable
Variables global to a project
Variables global to a window
Variables global to a report
Variables global to a set of procedures
How to use a global variable from a component
Global variable: Syntax
Declaring one or more global variables
Local variable
Local variable: Syntax
Declaring one or more local variables
Zombie local and global variables

WINDEV

WEBDEV

WINDEV Mobile

Others

See also

Global and local variable

Overview

Two types of variables are available:

Local variable: can only be used in the process where this variable was declared.
Global variable: can be used in all the processes related to the process in which this variable was declared.

Important: You must not declare two variables with the same name (especially a global variable and a local variable).

Versions 21 and later

This feature is available in Universal Windows 10 App mode.

This feature is available in Apple Watch mode.

New in version 21

This feature is available in Universal Windows 10 App mode.

This feature is available in Apple Watch mode.

This feature is available in Universal Windows 10 App mode.

This feature is available in Apple Watch mode.

Global variable

Variables global to a project

The global variables declared in the initialization process of a project can be used in all processes:

of project.
of window or page (processes of window or page, processes of its controls and processes of associated local procedures).
of report (processes of report, processes of its controls and processes of associated local procedures).

Variables global to a window

The global variables declared in the declaration process of the global variables of a window can be used in all processes:

of window.
of window controls.
of local procedures associated with the window.

Limits:

The global variables of a window cannot be used by its sibling windows.
The global variables declared in a child window cannot be used in its parent window.
When the window where the variable was declared is closed, this variable cannot be used anymore.

Note: Using a global variable in a child window of the declaration window

The variables declared global in a window are visible in the child windows of this window in the following cases:

If the Extern keyword is used to declare the variable in the child window.
If the variable name is prefixed by the window name.
If the variable is passed in parameter to the child window.

Variables global to a report

Global variables declared in the "Opening process" event of a report can be used in all processes:

of report.
of report controls.
of local procedures associated with the report.

Variables global to a set of procedures

The global variables declared in the initialization process of a set of procedures can be used in all processes:

of different procedures found in the set.
of current project.

How to use a global variable from a component

Since the purpose of a component is to be stand-alone, no global variable of the project should be used from this one.

However, the recommended method is as follows:

create a global variable in the component
in the component, create a procedure used to initialize these global variables.
from the initialization code of the project and whenever the value of the global variables of the project is modified, call this procedure to assign a similar value to the global variables of the component.

Global variable: Syntax

Declaring one or more global variables

GLOBAL
<Global variables>

Details of syntax


GLOBAL	Beginning of declaration of global variables.
<Global variables>	Global variables to declare.

Remark: PCS_SANS_TRADUCTION_US.

GLOBAL // All the declarations that follow are global variables
Subscript is int
CustomerName is string
Rate is real

LOCAL // All the declarations that follow are local variables
I is int
CustomerFName is string
Price is currency

Local variable

The local variables can only be used in the processes where they have been declared. The local variables are unknown outside these processes. These variables cannot be shared among several processes.

By default, a variable is local when it is declared.

Local variable: Syntax

Declaring one or more local variables

[LOCAL]
<Local variables>

Details of syntax


LOCAL	Beginning of declaration of local variables. The LOCAL keyword is optional.
<Local variables>	Local variables to declare.

Remark: PCS_SANS_TRADUCTION_US.

LOCAL // All the declarations that follow are local variables
I is int
CustomerFName is string
Price is currency

// All the declarations that follow are local variables
I is int
CustomerFName is string
Price is currency

Versions 23 and later

Zombie local and global variables

A local or global variable can become obsolete. This allows you to in know that this element must not be used anymore (but that it is not deleted yet).

To declare a variable as being obsolete, all you have to do is use the <Zombie> extension attribute.

The syntax is as follows:

In this syntax, the optional comment keyword is used to specify the text that will be displayed in the compilation error associated with the obsolete variable.

Example:

CustomerFirstName is string <zombie comment = "Don't use anymore - use the Customer structure">

New in version 23

Zombie local and global variables

A local or global variable can become obsolete. This allows you to in know that this element must not be used anymore (but that it is not deleted yet).

To declare a variable as being obsolete, all you have to do is use the <Zombie> extension attribute.

The syntax is as follows:

In this syntax, the optional comment keyword is used to specify the text that will be displayed in the compilation error associated with the obsolete variable.

Example:

CustomerFirstName is string <zombie comment = "Don't use anymore - use the Customer structure">

Zombie local and global variables

A local or global variable can become obsolete. This allows you to in know that this element must not be used anymore (but that it is not deleted yet).

To declare a variable as being obsolete, all you have to do is use the <Zombie> extension attribute.

The syntax is as follows:

In this syntax, the optional comment keyword is used to specify the text that will be displayed in the compilation error associated with the obsolete variable.

Example:

CustomerFirstName is string <zombie comment = "Don't use anymore - use the Customer structure">