Bind variables in SQL Developer

Question

I declared a bind variable called 'test_num' and assigned a value of 10 as shown below.
variable test_num number
BEGIN
:test_num := 10;
dbms_output.put_line ('The Test Value: ' || :test_num);
END;
When I execute the above program, the output is thrown as 'The Test Value: '. The value of test_num is not shown. I fear whether this issue is due to SQL Developer which i am using to execute this program.
Please let me know why the value is not getting printed
Thanks for your help!

Answer 1

I see the same issue you are seeing when using the bind variable. The bind variable works fine in SQL*Plus but not from SQL Developer.
From SQLPlus*
SQL> set serveroutput on
SQL> variable test_num number
SQL> BEGIN
2 :test_num := 10;
3 dbms_output.put_line ('The Test Value: ' || :test_num);
4 END;
5 /
The Test Value: 10
PL/SQL procedure successfully completed.
From SQLDeveloper*
set serveroutput on
variable test_num number
BEGIN
:test_num := 10;
dbms_output.put_line ('The Test Value: ' || :test_num);
END;
anonymous block completed
The Test Value: