The maximum lengths of varchar2 strings do not matter, only the assigned values : VARCHAR2 « PL SQL Data Types « Oracle PL/SQL Tutorial

1. Oracle PL/SQL Tutorial
2. PL SQL Data Types
3. VARCHAR2

SQL>
SQL> SET ECHO ON
SQL> SET SERVEROUTPUT ON
SQL> DECLARE
  2    fixed_length_10  CHAR(10);
  3    fixed_length_20  CHAR(20);
  4    var_length_10    VARCHAR2(10);
  5    var_length_20    VARCHAR2(20);
  6  BEGIN
  7
  8    
  9    var_length_10 := 'ZZZZ';
 10    var_length_20 := 'ZZZZ';
 11    IF var_length_20 = var_length_10 THEN
 12      DBMS_OUTPUT.PUT_LINE('Both Varchar2: '''
 13       || var_length_20 || ''' = '''
 14       || var_length_10 || '''');
 15    ELSE
 16      DBMS_OUTPUT.PUT_LINE('Both Varchar2: '''
 17        || var_length_20 || ''' NOT = '''
 18        || var_length_10 || '''');
 19    END IF;
 20  END;
 21  /
Both Varchar2: 'ZZZZ' = 'ZZZZ'

PL/SQL procedure successfully completed.

SQL>
SQL>
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