请问.存储过程/函数是否可允许参数为空呢

请教.存储过程/函数是否可允许参数为空呢?

SQL code

CREATE OR REPLACE FUNCTION GET_PERCENT (V_ARG1 NUMBER, V_ARG2 INT)RETURN VARCHAR2ISV_RESULT VARCHAR2(100);BEGIN  IF (V_ARG2 IS NULL) THENV_RESULT := TO_CHAR(ROUND(V_ARG1*100,2))||'%';ELSEV_RESULT := TO_CHAR(ROUND(V_ARG1*100,V_ARG2))||'%';END IF;RETURN V_RESULT;END;