DATA - data_options

Syntax

... [ VALUE val|{IS INITIAL} ]
[ READ-ONLY ].

Extras:

1. ... VALUE val|{IS INITIAL}

2. ... READ-ONLY

Effect

The two additions VALUE and READ-ONLY are specifically for data objects. They differentiate the DATA from the TYPES syntax.

Note

In addition to the VALUE and READ-ONLY additions, the syntax also allows the obsolete addition COMMON PART.

Addition 1

... VALUE val|{IS INITIAL}

Effect

Using the VALUE addition, you can define - for all forms (since Release 6.40) of the variable declaration - a start value val for the contents of the variable. This is used to initialize the variable at the time of its creation before the time LOAD-OF-PROGRAM. In the declaration part of an interface, the VALUE addition is not allowed for the DATA statement. The start value val can either be specified as a literal or as a constant already defined. If the data type of the specified start value does not match the data type of the declaration, it is converted according to the conversion rules for elementary data types. No start value must be specified for structures with numeric components.

Without the VALUE addition, or if IS INITIAL is specified, the content will be set to initial value. The initial values are dependent on the data type.

In the case of initial structures, the components are initial; initial reference variables contain the null reference that does not point to an object, and initial internal tables do not contain any rows.

Notes

A start value should be specified according to type. In particular, no longer values should be specified and, in the case of certain data types such as d and t, the length must be exact.
If you specify numbers with decimal places or if, in the scientific notation with Mantisse, you have an exponent as a start value for data objects of the data types p or f, you must remember that there are no literals for such numbers. Instead, the character literals must be specified with the appropriate content. These are then converted into the numeric data type according to the conversion rules for elementary data types. The same applies to byte-type data objects.

Addition 2

... READ-ONLY

Effect

This addition is solely possible in the public visibility area of a class or in an interface. It has the effect that an attribute declared using DATA is readable from an external point, but can only be changed using methods of the class or its subclasses.

A class attribute defined using READ-ONLY can be used outside of the class only at read positions in ABAP statements.

Note

The declaration of attributes with the READ-ONLY addition does not prevent methods of the references class for these attributes from getting outside in the form of reference variables or field symbols, in which case the attributes could thus be changed outside of the class.