Constants are numeric or text literals that have names. They are global in scope for an application. You can use them to organize applications by giving a common name to identical objects, or for program documentation.

You set the name and value in advance using ABF frames. You can change a set of constant names, such as those of menu items, to fit different contexts or to appear in another language. You cannot assign a new value to a constant while the application is running.

Constants can be used in any statement where a local variable can be used, except on the left side of assignment statements. However, a local variable overrides a constant with the same name.

Arrays or records cannot be made up of constants.

Constants can be of any simple data type, such as numeric or string, but cannot be of any complex data type, such as date or money.