Reverse a number in PL/SQL

Prerequisite PL/SQL introduction

In PL/SQL code groups of commands are arranged within a block. A block group related declarations or statements.
In declare part, we declare variables and between begin and end part, we perform the operations.

Here, first, we take three variables num, len, and revnum and assign the value in num and fin is the length of the number and after finding the length we start a loop from maximum length to starting length, we assign the num into revnum and print revnum.


Input : 123456
Output :654321
Input :87459
Output :95478

Below is the required implementation:





-- declare variable num , len 
-- and revnum of datatype varchar
 num varchar2(5):='12345';             
 len number(2);            
 revnum varchar2(5);        
-- Here we find the length of string
 len := length(num);                
-- here we starting a loop from max len to 1
 for i in reverse 1.. len
-- assigning the reverse number in revnum               
 revnum := revnum || substr(num,i,1);
 end loop;
-- Print the Result
dbms_output.put_line('given number ='|| num); 
dbms_output.put_line('reverse number ='|| revnum); 
-- Program End


Output :

reverse of number is 654321.

My Personal Notes arrow_drop_up

Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using or mail your article to See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.

Article Tags :
Practice Tags :

Be the First to upvote.

Please write to us at to report any issue with the above content.