SET SERVEROUTPUT ON 
SET VERIFY OFF
ACCEPT A NUMBER PROMPT 'ENTER THE NUMBER:'
DECLARE
       A NUMBER := &A;
       REV NUMBER:=0;
       REM NUMBER;
BEGIN
    DBMS_OUTPUT.PUT_LINE('ORIGINAL NUMBER: '|| A);
    
    WHILE (A>0)
    LOOP
      REM:= MOD(A,10);
      REV :=(REV *10)+REM;
      A := TRUNC(A / 10);
    END LOOP;
    
    DBMS_OUTPUT.PUT_LINE('Reversed Number: ' || REV);
    
END;
/

PL/SQL Online Compiler

Write, Run & Share PL/SQL code online using OneCompiler's Oracle PL/SQL online editor and compiler for free. It's one of the robust, feature-rich online editor and compiler for Oracle PL/SQL running on latest version 23c (23.3.0.0). Getting started with the OneCompiler's Oracle PL/SQL editor is really simple and pretty fast. The editor shows sample boilerplate code when you choose language as 'PL/SQL' and start writing code to learn and test online without worrying about tedious process of installation.

About PL/SQL

PL/SQL is procedural extension for SQL created by Oracle. It is by default embedded into the Oracle Database. PL/SQL program units are compiled and stored inside the Oracle Database which results in optimal execution times as the PL/SQL and SQL run within the same server process.

Syntax help

Following is the syntax structure for the PL/SQL code blocks

DECLARE 
   <declarations section> 
BEGIN 
   <executable command(s)>
EXCEPTION 
   <exception handling> 
END;

Example

DECLARE 
   message  varchar2(100):= 'Hello, World!'; 
BEGIN 
   dbms_output.put_line(message); 
END; 
/

Named procedures

CREATE OR REPLACE FUNCTION 
hello_user
   (user_name IN VARCHAR2) 
    RETURN VARCHAR2
IS
BEGIN
   RETURN 'Hello ' || user_name;
END hello_user;
/

BEGIN
   dbms_output.put_line(hello_user('Peter'));
END;
/

Exception handling

BEGIN
  DBMS_OUTPUT.put_line (1/0);
EXCEPTION
  WHEN OTHERS
  THEN
    DBMS_OUTPUT.put_line ('error is: ' || SQLERRM);
END;