Drop all tables in Oracle

-- drop all tables in current schema
DECLARE
   table_name VARCHAR2(30);
   CURSOR usertables IS SELECT * FROM user_tables WHERE table_name NOT LIKE 'BIN$%';
BEGIN
   FOR next_row IN usertables
   LOOP
      EXECUTE IMMEDIATE 'drop table ' || next_row.table_name || ' cascade constraints';
   END LOOP;
END;
/