How to Initialization collections?

Only Nested tables and varrays need initialization.

To initialize a collection, you use the “constructor” of the collection which name is the same as the collection.

Nested tables

Declare

   TYPE TYP_NT_NUM IS TABLE OF NUMBER;

    Nt_tab TYP_NT_NUM;

Begin

   Nt_tab := TYP_NT_NUM( 5, 10, 15, 20 ) ;

End;

Varrays

Declare

   TYPE TYP_V_DAY IS VARRAY(7) OF VARCHAR2(15);

   v_tab TYP_V_DAY;

Begin

   v_tab := TYP_NT_NUM( ‘Sunday’,’Monday’,’Tuesday’,’Wedneday’,’Thursday’,’Friday’,’Saturday’ ) ;

End;

It is not required to initialize all the elements of a collection. You can either initialize no element. In this case, use an empty constructor.

v_tab := TYP_NT_NUM();

This collection is empty, which is different than a NULL collection (not initialized).

Index-by tables

Declare

   TYPE TYP_TAB IS TABLE OF NUMBER INDEX BY PLS_INTEGER;

   my_tab TYP_TAB;

Begin

   my_tab(1) := 5 ;

   my_tab(2) := 10 ;

   my_tab(3) := 15 ;

End;