Question about varray's not null in Oracle

If the not null restriction is added when varray is defined, the element of this varray cannot be null.

Definition:

Create or replace type integer_varray
As varray (5) of integer not null;
/

 

Then there is a PLSQL block as follows:

Declare

-- Declare and initialize a null set of rows.
Varray_integer integer_varray: = integer_varray ();

Begin

-- Loop through all records to print the varray contents.
For I in 1 .. varray_integer.limit Loop

-- Initialize row.
Varray_integer.extend;

/* No value assignment. If no value assignment is null, it should be compiled incorrectly. The result is compiled smoothly */

End loop;

 

-- Print to console how many rows are initialized.
Dbms_output.put ('integer varray initialized ');
Dbms_output.put_line ('[' | varray_integer.count | ']');

-- Varray_integer (1): = NULL;

For I in 1 .. varray_integer.count Loop

-- Print the contents.
Dbms_output.put ('integer varray ['| I |'] ');
Dbms_output.put_line ('[' | varray_integer (I) | ']');

If (varray_integer (I) is null) then

/* I thought this should not be executed, and the result will be printed */
Dbms_output.put_line ('integer varray ['| I |'] '|' is null ');
End if;

End loop;

End;
/

 

The running result is as follows:/* The running is normal, and the display element is null, which is a conflict of Definitions */

Integer varray initialized [5]
Integer varray [1] []
Integer varray [1] is null
Integer varray [2] []
Integer varray [2] is null
Integer varray [3] []
Integer varray [3] is null
Integer varray [4] []
Integer varray [4] is null
Integer varray [5] []
Integer varray [5] is null

 

The test environment is:

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Oracle Database 10g Enterprise Edition Release 10.2.0.1.0-Prod
PL/SQL release 10.2.0.1.0-Production
Core 10.2.0.1.0 Production
TNS for 32-bit windows: Version 10.2.0.1.0-Production
Nlsrtl version 10.2.0.1.0-Production