Constants cannot be changed : CONSTANT « PL SQL Data Types « Oracle PL/SQL Tutorial

1. Oracle PL/SQL Tutorial
2. PL SQL Data Types
3. CONSTANT

SQL>
SQL> SET SERVEROUTPUT ON
SQL> DECLARE
  2     v_first_name CONSTANT VARCHAR2(50) := 'Ron';
  3  BEGIN
  4     v_first_name := 'Ronald';
  5  EXCEPTION
  6     WHEN OTHERS
  7     THEN
  8        DBMS_OUTPUT.PUT_LINE(SQLERRM);
  9  END;
 10  /
   v_first_name := 'Ronald';
   *
ERROR at line 4:
ORA-06550: line 4, column 4:
PLS-00363: expression 'V_FIRST_NAME' cannot be used as an assignment target
ORA-06550: line 4, column 4:
PL/SQL: Statement ignored


SQL>