ABAP Keyword Documentation → ABAP - Reference → Program Flow → Expressions and Functions for Logical Expressions → log_exp - Logical Expressions → log_exp - Predicates → log_exp - IS
log_exp - IS BOUND
Other versions: 7.31 | 7.40 | 7.54
Syntax
... ref IS [NOT] BOUND ...
Effect
This logical expression checks whether a reference variable contains a valid reference. For ref, you must specify a data object defined with addition REF TO or a
functional method, whose return value is typed with REF TO.
A data reference is valid if it can be dereferenced. An object reference is valid if it points to an object.
When using addition NOT, the expression is true if the reference variable does not contain a valid reference.
Note
A non-initial reference variable that contains a heap reference is generally always valid (since it keeps an object alive). Only heap references that point to rows from internal tables can become invalid when rows are deleted. A data reference variable that contains a stack reference, on the other hand, can become invalid even if the reference data object is removed from the stack.
Example
The logical expression in the IF statement is false. The data reference dref contains a reference to a deleted table row.
itab TYPE TABLE OF ...
FIELD-SYMBOLS <fs> TYPE ANY.
READ TABLE itab REFERENCE INTO dref
WITH ...
...
CLEAR itab.
...
IF dref IS BOUND.
ASSIGN dref->* TO <fs>.
ENDIF.