Hash table and function module input

Question

Hi ABAP Expert,
Please advise what happening if i am passing the intertal table (hashtable) become input of function module (table).
so insite the function module is this table still hashtable type or just normal internal table ?
Thank you and Regards
Fernand

Answer 1

Typing of such parameter should be either generic (i.e ANY TABLE) or fully specified (HASHED/SORTED/STANDARD TABLE). In both cases when you pass i.e. HASHED table to that formal parameter the dynamic type will be inherited by the actual paremeter.
This means that inside the function module you will not be able to use HASHED table "banned" statement i.e. not appending to this table. The system must be fully convinced about the type of passed parameter to allow certain access. Without that knowledge it won't pass you through the syntax checker or will trigger runtime error.
I.e
"1) parameter is typed
CHANGING
   C_TAB type ANY TABLE
"here you can't use STANDARD/SORTED table specific statements as the dynamic type of param might be HASHED TABLE
append ... to c_tab.  "error during runtime
"2) parameter is typed
CHANGING
   C_TAB type HASHED TABLE
"here system explicitly knows that dynamic type is the same as static one so you can append to this table too
append ... to c_tab.  "syntax error before runtime
So the anwser to your question
so insite the function module is this table still hashtable type or just normal internal table ?
is...
During syntax check system takes static type of table and shouts if table related operation is not allowed for this kind.
During runtime system takes dynamic type of the table and checks whether particular statement is allowed for this kind of table, if not triggers an exception.
Regards
Marcin