Question

I am trying to change the value of upper bound in For loop ,but the Loop is running till the upper bound which was defined in the starting.

According to logic loop should go infinite, since value of v_num is always one ahead of i,But loop is executing three time.Please explain

This is the code

    DECLARE
    v_num number:=3;
    BEGIN
        FOR i IN 1..v_num LOOP
           v_num:=v_num+1;
           DBMS_OUTPUT.PUT_LINE(i ||'  '||v_num);
     END LOOP;
    END;
Ouput Coming

    1  4
    2  5
    3  6

Answer 1

This behavior is as specified in the documentation:

FOR-LOOP
…
The range is evaluated when the FOR loop is first entered and is never re-evaluated.

(Oracle Documentation)