What does it do? mem_area is used to specify the memory area that is assigned to a field symbol with the statement ASSIGN:
The first variant static_dobj is a static variant in which a statically known data object or part of such an object is assigned.
The second, third and fourth variants are dynamic.
The variants dynamic_dobj are used for general dynamic access to data objects.
The variants dynamic_components are used for dynamic access to components of structures.
The variants dynamic_access are used for dynamic access to the attributes of classes.
The fifth variant assigns the result of a writable expression . For an inline declaration of the field symbol with FIELD-SYMBOL(<(><)>), its typing is done with the data type of mem_area for the static variant and when specifying a writable expression. For the dynamic variants the typing is done with the generic type data. The variants differ as to how the system behaves after an unsuccessful assignment:
For the static variant, the return code sy-subrc is not set. The addition ELSE UNASSIGN is used implicitly and cannot be specified.
For the dynamic variants, the statement ASSIGN sets the return code sy-subrc or can raise an exception. The addition ELSE UNASSIGN can be specified.
When a ABAP Alternative 3@3@>table expression is specified, the statement ASSIGN sets the return code sy-subrc. The addition ELSE UNASSIGN can be specified.
When assigning constructor operators:
ABAP Alternative 1@1@>NEW the return code sy-subrc is set by the constructor operator.
ABAP Alternative 2@2@> CASE the return code sy-subrc is not set. The addition ELSE UNASSIGN must not be specified because an assignment of a constructor operator is either successful or raises an exception.
Latest notes:
In an internal table with a header line, either the header line or the table body can be assigned to a field symbol. In the statement ASSIGN, the name of an internal table with a header line addresses the header line. To address the table body, [] must be appended to the name as usual. A field symbol to which a table body is assigned behaves in the same way in operand positions as a table without a header line.
Field symbols to which data objects or parts of data objects are assigned in the heap act in a memory-preserving way, like heap references.
In an inline declaration of the field symbol with FIELD-SYMBOL(<(><)>), the data type of the assigned memory area determines its typing. NON_V5_HINTS ABAP_HINT_END
