how to use truncate/drop/create in plsql

One can call DDL statements like CREATE, DROP, TRUNCATE, etc. from PL/SQL by using the "EXECUTE IMMEDIATE" statement (native SQL).
Examples:

begin
EXECUTE IMMEDIATE 'CREATE TABLE X(A DATE)';
end;
begin execute Immediate 'TRUNCATE TABLE emp'; end;
DECLARE
var VARCHAR2(100);
BEGIN
var := 'CREATE TABLE temp1(col1 NUMBER(2))';
EXECUTE IMMEDIATE var;
END;