SQL & PL/SQL

Hi,
I've developed the SP that I describe below:

  
CREATE OR REPLACE PROCEDURE P_INS_OPE       
  (
    NAME VARCHAR2
  , GROUP_ VARCHAR2
  , RESULT_ OUT NUMBER
  ) AS
  BEGIN
  DECLARE
    v_name VARCHAR2(50);
    v_group VARCHAR2(100);
    v_result NUMBER := 0;
  BEGIN
    v_name := NAME;
    v_group := GROUP_;
    
    INSERT INTO mr_ope(name, group_) VALUES (v_name, v_group)
    RETURNING id 
    INTO v_result;
    COMMIT;
    
    RESULT_ := v_result;
  END;
  END P_INS_OPE;

and I would like to know if is necessary to initialize in declare section the varchar2 variables
with a blank space like this?

 v_name VARCHAR2(50) := ' ';
 v_group VARCHAR2(100) := ' ';

thanks in advanced