SQL>
SQL>
SQL> set serveroutput on
SQL>
SQL> VARIABLE v_String1 VARCHAR2(20);
SQL> VARIABLE v_String2 VARCHAR2(20);
SQL>
SQL> BEGIN
2 :v_String1 := 'Hello';
3 :v_String2 := ' World!';
4 END;
5 /
PL/SQL procedure successfully completed.
SQL>
SQL> ALTER SESSION SET EVENTS '10046 trace name context forever, level 4';
Session altered.
SQL>
SQL>
SQL> BEGIN
2 DBMS_OUTPUT.PUT_LINE(:v_String1 || :v_String2);
3 END;
4 /
Hello World!
PL/SQL procedure successfully completed.
SQL>
SQL>