get_user(post)_meta

About get_user(post)_meta
I think that the function “get_user(post)_meta” needs a parameter for default value
sometimes we just need a default value to display.
for example: to get one’s gender,if he/she doesn’t add gender,when we use get_user_meta($user_id,’gender’,true) but the result is empty,so in this case we can use a default value like something “secrecy”,
I think of it like this get_user_meta($user_id,’gender’,true,’secrecy’)