How Many Data Types Are Supported?

PL/SQL supports two groups of data types:
SQL Data Types - All data types used for table columns.
PL/SQL Special Data Types - Like BOOLEAN or PLS_INTEGER.
The script below shows some data type examples:
SQL> set serveroutput on;
SQL> DECLARE
2 title VARCHAR(;
3 salary NUMBER;
4 seeking_job BOOLEAN;
5 BEGIN
6 title := 'DBA';
7 salary := 50000;
8 seeking_job := TRUE;
9 DBMS_OUTPUT.PUT_LINE('Job Title: ' || title);
10 DBMS_OUTPUT.PUT_LINE('Expected salary: ' || TO_CHAR(salary));
11 END;
12 /
Job Title: DBA
Expected salary: 50000