SQL> var jobno number
SQL> exec dbms_job.submit(:jobno, 'begin null; end;');

PL/SQL procedure successfully completed.

SQL> print jobno

     JOBNO
----------
        47

SQL> col what format a50
SQL> select job, what from user_jobs;

       JOB WHAT
---------- --------------------------------------------------
        47 begin null; end;

1 row selected.

SQL> exec dbms_job.remove(&jobno);
Enter value for jobno: 47

PL/SQL procedure successfully completed.

SQL> select job, what from user_jobs;

no rows selected