About structures

General information

A structure is a collection of one or more variables (sometimes called elements) that you want to group together under a single name. The variables can have any datatype, including standard and object datatypes and other structures.

Defining structures

When you define a structure in the Structure painter or an object painter (such as Window, Menu, or User Object), you are creating a structure definition. To use the structure, you must declare it. When you declare it, an instance of it is automatically created for you. When it goes out of scope, the structure is destroyed.

For details about defining structures, see the the section called “Working with Structures” in Users Guide.

Declaring structures

If you have defined a global structure in the Structure painter called str_emp_data, you can declare an instance of the structure in a script or in an object's instance variables. If you define the structure in an object painter, you can only declare instances of the structure in the object's instance variables and scripts.

This declaration declares two instances of the structure str_emp_data:

str_emp_data str_emp1, str_emp2

Referring to structure variables

In scripts, you refer to the structure's variables using dot notation:


These statements assign values to the variables in str_emp_data:

str_emp1.emp_id = 100
str_emp1.emp_lname = "Jones"
str_emp1.emp_salary = 200

str_emp2.emp_id = 101
str_emp2.emp_salary = str_emp1.salary * 1.05

Using structures as instance variables

If the structure is declared as part of an object, you can qualify the structure name using dot notation:


Suppose that this declaration is an instance variable of the window w_customer:

str_cust_data str_cust1

The following statement in a script for the object refers to a variable of str_cust_data. The pronoun This is optional, because the structure declaration is part of the object:


The following statement in a script for some other object qualifies the structure with the window name: