REVERS SQL

/* REVERSE number*/
DECLARE
    ans VARCHAR(30);

    no2 VARCHAR(30):='001';
    rev VARCHAR(30);
    l NUMBER;
BEGIN
    DBMS_OUTPUT.put_line('no => ' || no2);

    l:=LENGTH(no2);
    FOR i IN REVERSE 1..l LOOP
        rev:=CONCAT(rev,SUBSTR(no2,i,1));
    END LOOP;

    DBMS_OUTPUT.put_line( rev|| ' is REVERS ');

END;